Attachment A (Authorized CSO Outfalls and Responsible Parties)
U.S. Environmental Protection Agency · from the EPA · 84 pages · 4.9 MB
open the file ↗ · original at the source ↗
NPDES Permit No. MA0103284
2023 Reissuance
Attachment A: CSO Outfalls and Responsible Party
Page 1 of 3
Outfall No.
Responsible
Permittee or Co-
permittee
Receiving Water Latitude and
Longitude
MWR010 Massachusetts Water
Resources Authority Charles River 42° 21’ 6” N,
71° 6’ 22” W
MWR018 Massachusetts Water
Resources Authority Charles River 42° 21’ 10” N,
71° 5’ 15” W
MWR019 Massachusetts Water
Resources Authority Charles River 42° 21’ 18” N,
71° 4’ 51” W
MWR020 Massachusetts Water
Resources Authority Charles River 42° 21’ 24” N,
71° 4’ 34” W
MWR023 Massachusetts Water
Resources Authority Charles River 42° 21’ 6” N,
71° 5’ 33” W
BOS046 Boston Water and
Sewer Commission Muddy River 42° 20’ 30” N,
71° 5’ 34’ w
BOS013 Boston Water and
Sewer Commission Boston Inner Harbor 42° 23’ 3” N,
71° 2’ 22” W
BOS014 Boston Water and
Sewer Commission Boston Inner Harbor 42° 22’ 58” N,
71° 1’ 38” W
BOS009 Boston Water and
Sewer Commission Boston Inner Harbor 42° 22’ 13” N,
71° 2’ 39” W
BOS010 Boston Water and
Sewer Commission Boston Inner Harbor 42° 22’ 24” N,
71° 2’ 32” W
BOS012 Boston Water and
Sewer Commission Boston Inner Harbor 42° 22’ 40” N,
71° 2” 32” W
BOS057 Boston Water and
Sewer Commission Boston Inner Harbor 42° 21’ 51” N,
71° 2’ 58” W
BOS060 Boston Water and
Sewer Commission Boston Inner Harbor 42° 21’ 34” N,
71° 2’ 54” W
BOS003 Boston Water and
Sewer Commission Boston Inner Harbor 42° 21’ 28” N,
71° 1’ 40” W
BOS004 Boston Water and
Sewer Commission Boston Inner Harbor 42° 21’ 53” N,
71° 1’ 37” W
CHE008 City of Chelsea Chelsea River 42° 23’ 41” N,
71° 1’ 9” W
BOS062 Boston Water and
Sewer Commission Fort Point Channel 42° 21’ 16” N,
71° 3’ 4” W
BOS064 Boston Water and
Sewer Commission Fort Point Channel 42° 21’ 5” N,
71° 3’ 10” W
BOS065 Boston Water and
Sewer Commission Fort Point Channel 42° 20’ 55” N,
71°3’ 16” W
BOS068 Boston Water and
Sewer Commission Fort Point Channel 42° 20’ 42” N,
71° 3’ 34” W
BOS070 Boston Water and
Sewer Commission Fort Point Channel 42° 20’ 34” N,
71° 3’ 40” W
NPDES Permit No. MA0103284
2023 Reissuance
Attachment A: CSO Outfalls and Responsible Party
Page 2 of 3
Outfall No.
Responsible
Permittee or Co-
permittee
Receiving Water Latitude and
Longitude
BOS073 Boston Water and
Sewer Commission Fort Point Channel 42° 20’ 52” N,
71° 3’ 13” W
BOS076 Boston Water and
Sewer Commission Reserve Channel 42° 20’ 23” N,
71° 2’ 31” W
BOS078 Boston Water and
Sewer Commission Reserve Channel 42° 20’ 19” N,
71° 2’ 24” W
BOS079 Boston Water and
Sewer Commission Reserve Channel 42° 20’ 31” N,
71° 2’ 8” W
BOS080 Boston Water and
Sewer Commission Reserve Channel 42° 20’ 30” N,
71° 1’ 31” W
BOS081 Boston Water and
Sewer Commission North Dorchester Bay 42° 19’ 57” N,
71°1’ 30”W
BOS082 Boston Water and
Sewer Commission North Dorchester Bay 42° 19’ 47” N,
71° 1’ 49”W
BOS084 Boston Water and
Sewer Commission North Dorchester Bay 42° 19’ 43” N,
71° 2’ 29” W
BOS085 Boston Water and
Sewer Commission North Dorchester Bay 42° 19’ 40” N,
71° 2’ 43” W
BOS086 Boston Water and
Sewer Commission North Dorchester Bay 42° 19’ 36” N,
71° 2’ 44” W
MWR003 Massachusetts Water
Resources Authority Alewife Brook 42° 22’ 8” N,
71° 3’ 39” W
CAM001 City of Cambridge Alewife Brook 42° 24’ 7” N,
71° 8’ 7” W
CAM002
• CAM002A
• CAM002B
(temporarily
closed)
City of Cambridge Alewife Brook 42° 24’ 4” N,
71° 8’ 10” W
CAM401A City of Cambridge Alewife Brook 42° 23’ 44” N,
71° 8’ 38” W
CAM401B City of Cambridge Alewife Brook 42° 24’ 4” N,
71° 8’ 10”W
CAM005 City of Cambridge Charles River 42° 22’ 25” N,
71° 7’ 58” W
CAM007 City of Cambridge Charles River 42° 22’ 24” N,
71° 7’ 37” W
CAM009
(temporarily
closed)
City of Cambridge Charles River 42° 22’ 10” N,
71° 07’24” W
NPDES Permit No. MA0103284
2023 Reissuance
Attachment A: CSO Outfalls and Responsible Party
Page 3 of 3
Outfall No.
Responsible
Permittee or Co-
permittee
Receiving Water Latitude and
Longitude
CAM011
(temporarily
closed)
City of Cambridge Charles River 42° 22’ 8” N,
71° 07’ 4” W
CAM017 City of Cambridge Charles River 42° 21’ 53” N,
71° 4’ 35” W
SOM001A City of Somerville Alewife Brook 42° 24’ 9” N,
71° 8’ 6” W
SOM007A City of Somerville Mystic River 42° 23’ 38” N,
71° 4’ 34” W
BOS017 Boston Water and
Sewer Commission Mystic River 42° 23’8” N,
71° 4’ 8” W
BOS019 Boston Water and
Sewer Commission Mystic River 42° 22’ 48” N,
71° 3’ 4” W
CHE003 City of Chelsea Mystic River 42° 23’ 13” N,
71° 2’ 27” W
CHE004 City of Chelsea Mystic River 42° 23’ 12” N,
71° 2’ 21” W
CHE008 City of Chelsea Chelsea River 42° 23’ 41” N,
71° 1’ 9” W
Draft Permit NPDES Permit No. MA0103284
2023 Reissuance
A ttachment B : MWRA Member Communities named as Co-permittees
Page 1 of 5
MWRA Sewer Member Communities
and Co-permittees to NPDES Permit MA0103284
with individual permit number
Permit
Number
Co-permittee Responsibilities
MAC013284 Town of Arlington
Water and Sewer Department
51 Grove Street
Arlington, MA 02476
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC023284 Town of Ashland
Department of Public Works
20 Ponderosa Road
Ashland, MA 01721
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC033284 Town of Bedford
Department of Public Works
314 Great Road
Bedford, MA 01730
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC043284 Town of Belmont
Department of Public Works
19 Moore Street
Belmont, MA 02478
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC063284 Town of Braintree
Department of Public Works
P.O. Box 850903
Braintree, MA 02185-0903
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC073284 Town of Brookline
Department of Public Works
333 Washington Street
Brookline, MA 02445
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC083284 Town of Burlington
Department of Public Works
25 Center Street
Burlington, MA 01803
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC103284 Town of Canton
Department of Public Works
801 Washington Street
Canton, MA 02021
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC123284 Town of Dedham
Department of Public Works
55 River Street
Dedham, MA 02026
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
Fact Sheet NPDES Permit No. MA0103284
2023 Reissuance
Appendix B : MWRA Member Communities named as Co-permittees
Page 2 of 5
Permit
Number
Co-permittee Responsibilities
MAC133284 City of Everett
Department of Public Works
19 Norman Street
Everett, MA 02149
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC143284 City of Framingham
Department of Public Works
110 Western Avenue
Framingham, MA 01701
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC153284 Town of Hingham
Department of Public Works
25 Bare Cove Park Drive
Hingham, MA 02043
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC163284 Town of Holbrook
Department of Public Works
50 N. Franklin Street
Holbrook, MA 02343
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC173284 Town of Lexington
Water & Sewer Department
201 Bedford Street
Lexington, MA 02420
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC183284 City of Malden
Department of Public Works
356 Commercial Street
Malden, MA 02148
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC193284 City of Medford
Department of PublicWorks
21 James Street
Medford, MA 02155
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC203284 City of Melrose
Department of PublicWorks
72 Tremont St.
Melrose, MA 02176
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC213284 Town of Milton
Deaprtment of Public Works
629 Randolph Avenue
Milton, MA 02186
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC223284 Town of Natick
Director of Public Works
75 West Street
Natick, MA 01760
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
Fact Sheet NPDES Permit No. MA0103284
2023 Reissuance
Appendix B : MWRA Member Communities named as Co-permittees
Page 3 of 5
Permit
Number
Co-permittee Responsibilities
MAC233284 Town of Needham
Department of Public Works
500 Dedham Avenue
Needham, MA 02492
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC243284 City of Newton
Department of Public Works
1000 Commonwealth Avenue
Newton, MA 02459
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC253284 Town of Norwood
Department of Public Works
566 Washington Street
Norwood, MA 02062
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC263284 City of Quincy
Department of Public Works
55 Sea Street
Quincy, MA 02169
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC273284 Town of Randolph
Department of PublicWorks
41 South Main Street
Randolph, MA 02368
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC283284 Town of Reading
Department of Public Works
16 Lowell Street
Reading, MA 01867
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC293284 City of Revere
Department of PublicWorks
321 Rear Charger Street
Revere, MA 02151
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC313284 Town of Stoneham
Public Works Department
16 Pine Street
Stoneham, MA 02180
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC323284 Town of Stoughton
Department of PublicWorks
950 Central Street
Stoughton, MA 02072
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC333284 Town of Wakefield
Department of Public Works
1 Lafayette Street
Wakefield, MA 01880
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
Fact Sheet NPDES Permit No. MA0103284
2023 Reissuance
Appendix B : MWRA Member Communities named as Co-permittees
Page 4 of 5
Permit
Number
Co-permittee Responsibilities
MAC343284 Town of Walpole
Department of PublicWorks
135 School Street
Walpole, MA 02081
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC353284 City of Waltham
Water & Sewer Division
165 Lexington Street
Waltham, MA 02452
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC363284 Town of Watertown
Department of Public Works
124 Orchard Street
Watertown, MA 02472
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC373284 Town of Wellesley
Department of Public Works
20 Municipal Way
Wellesley, MA 02481
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC383284 Town of Westwood
Department of PublicWorks
50 Carby Street
Westwood, MA 02090
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC393284 Town of Weymouth
Department of PublicWorks
120 Winter Street
Weymouth, MA 02188
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC403284 Town of Wilmington
Water & Sewer Division
121 Glen Road
Wilmington, MA 01887
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC413284 Town of Winchester
Department of PublicWorks
15 Lake Street
Winchester, MA 01890
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC423284 Town of Winthrop
Department of Public Works
100 Kennedy Drive
Winthrop, MA 02152
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
MAC433284 City of Woburn
Public Works Sewer Division
50 North Warren Street
Woburn, MA 01801
Draft Permit Part I.C., Part I.E., Part
I.F., and Part I. J.
Permit
Number
Co - permittee Responsibilities
MAC053284 City of Boston
Boston Water and Sewer Commission
980 Harrison Avenue
Boston, MA 02119
Draft Permit Part I.B., Part
I.C., Part I.D., Part I.E., Part
I.F., and Part I.J.
MAC093284 City of Cambridge
Department of Public Works
147 Hampshire Street
Cambridge, MA 02139
Draft Permit Part I.B., Part
I.C., Part I.D., Part I.E., Part
I.F., and Part I.J.
MAC113284 City of Chelsea
Department of Public Works
500 Broadway
Chelsea, MA 02150
Draft Permit Part I.B., Part
I.C., Part I.D., Part I.E., Part
I.F., and Part I.J.
MAC 30 3284 City of Somerville
Department of Public Works
17 Franey Street
Somerville, MA 02144
Draft Permit Part I.B., Part
I.C., Part I.D., Part I.E., Part
I.F., and Part I.J.
Fact Sheet NPDES Permit No. MA0103284
2023 Reissuance
Appendix B : MWRA Member Communities named as Co-permittees
Page 5 of 5
MWRA Sewer Member Communities
and CSO-responsible Co-permittees
to NPDES Permit MA0103284
with individual permit number
Page 1 of 10
ATTACHMENT C
MARINE ACUTE
TOXICITY TEST PROCEDURE AND PROTOCOL
July 2012
(updated links/addresses 2023)
I. GENERAL REQUIREMENTS
The permittee shall conduct acceptable acute toxicity tests in accordance with the appropriate
test protocols described below:
• 2007.0 - Mysid Shrimp (Americamysis bahia) definitive 48 hour test.
• 2006.0 - Inland Silverside (Menidia beryllina) definitive 48 hour test.
Acute toxicity data shall be reported as outlined in Section VIII.
II. METHODS
The permittee shall use the most recent 40 CFR Part 136 methods. Whole Effluent Toxicity
(WET) Test Methods and guidance may be found at:
https://www.epa.gov/cwa-methods/whole-effluent-toxicity-methods
The permittee shall also meet the sampling, analysis and reporting requirements included in this
protocol. This protocol defines more specific requirements while still being consistent with the
Part 136 methods. If, due to modifications of Part 136, there are conflicting requirements
between the Part 136 method and this protocol, the permittee shall comply with the requirements
of the Part 136 method.
III. SAMPLE COLLECTION
A discharge and receiving water sample shall be collected. The receiving water control sample
must be collected immediately upstream of the permitted discharge’s zone of influence. The
acceptable holding times until initial use of a sample are 24 and 36 hours for on-site and off-site
testing, respectively. A written waiver is required from the regulating authority for any holding
time extension. Sampling guidance dictates that, where appropriate, aliquots for the analysis
required in this protocol shall be split from the samples, containerized and immediately
preserved, or analyzed as per 40 CFR Part 136. EPA approved test methods require that samples
collected for metals analyses be preserved immediately after collection. Testing for the presence
of total residual chlorine 1 (TRC) must be analyzed immediately or as soon as possible, for all
effluent samples, prior to WET testing. TRC analysis may be performed on-site or by the toxicity
testing laboratory and the samples must be dechlorinated, as necessary, using sodium thiosulfate
1 For this protocol, total residual chlorine is synonymous with total residual oxidants.
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prior to sample use for toxicity testing. If performed on site the results should be included on the
chain of custody (COC) presented to WET laboratory.
Standard Methods for the Examination of Water and Wastewater describes dechlorination of
samples (APHA, 1992). Dechlorination can be achieved using a ratio of 6.7 mg/L anhydrous
sodium thiosulfate to reduce 1 mg/L chlorine. If dechlorination is necessary, a thiosulfate control
consisting of the maximum concentration of thiosulfate used to dechlorinate the sample in the
toxicity test control water must also be run in the WET test.
All samples submitted for chemical and physical analyses will be analyzed according to Section
VI of this protocol. Grab samples must be used for pH, temperature, and total residual chlorine
(as per 40 CFR Part 122.21).
All samples held for use beyond the day of sampling shall be refrigerated and maintained at a
temperature range of 0-6 o C.
IV. DILUTION WATER
Samples of receiving water must be collected from a reasonably accessible location in the
receiving water body immediately upstream of the permitted discharge’s zone of influence.
Avoid collection near areas of obvious road or agricultural runoff, storm sewers or other point
source discharges and areas where stagnant conditions exist. EPA strongly urges that screening
for toxicity be performed prior to the set up of a full, definitive toxicity test any time there is a
question about the test dilution water's ability to achieve test acceptability criteria (TAC) as
indicated in Section V of this protocol. The test dilution water control response will be used in
the statistical analysis of the toxicity test data. All other control(s) required to be run in the test
will be reported as specified in the Discharge Monitoring Report (DMR) Instructions,
Attachment F, page 2,Test Results & Permit Limits.
The test dilution water must be used to determine whether the test met the applicable TAC.
When receiving water is used for test dilution, an additional control made up of standard
laboratory water (0% effluent) is required. This control will be used to verify the health of the
test organisms and evaluate to what extent, if any, the receiving water itself is responsible for any
toxic response observed.
If dechlorination of a sample by the toxicity testing laboratory is necessary a “sodium
thiosulfate” control, representing the concentration of sodium thiosulfate used to adequately
dechlorinate the sample prior to toxicity testing, must be included in the test.
If the use of alternate dilution water (ADW) is authorized, in addition to the ADW test control,
the testing laboratory must, for the purpose of monitoring the receiving water, also run a
receiving water control.
If the receiving water is found to be, or suspected to be toxic or unreliable, ADW of known
quality with hardness similar to that of the receiving water may be substituted. Substitution is
July 2012
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Page 3 of 10
species specific meaning that the decision to use ADW is made for each species and is based on
the toxic response of that particular species. Substitution to an ADW is authorized in two cases.
The first case is when repeating a test due to toxicity in the site dilution water requires an
immediate decision for ADW use by the permittee and toxicity testing laboratory. The second is
when two of the most recent documented incidents of unacceptable site dilution water toxicity
require ADW use in future WET testing.
For the second case, written notification from the permittee requesting ADW use and written
authorization from the permit issuing agency(s) is required prior to switching to a long-term use
of ADW for the duration of the permit.
Written requests for use of ADW with supporting documentation must be sent electronically to
the NPDES Applications Coordinator in EPA Water Division (WD) at the following email
address: R1NPDESReporting@epa.gov
Note: USEPA Region 1 retains the right to modify any part of the alternate dilution water policy
stated in this protocol at any time. Any changes to this policy will be documented in the annual
DMR posting.
See the EPA Region 1 website at : www.epa.gov/aboutepa/epa-region-1-new-england (click
on NPDES, EPA Permit Attachments, Self-Implementing Alternate Dilution Water Guidance)
for important details on alternate dilution water substitution requests.
V. TEST CONDITIONS AND TEST ACCEPTABILITY CRITERIA
EPA Region 1 requires tests be performed using four replicates of each control and effluent
concentration because the non-parametric statistical tests cannot be used with data from fewer
replicates. The following tables summarize the accepted Americamysis and Menidia toxicity test
conditions and test acceptability criteria:
July 2012
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Page 4 of 10
EPA NEW ENGLAND EFFLUENT TOXICITY TEST CONDITIONS FOR THE MYSID,
AMERICAMYSIS BAHIA 48 HOUR TEST 1
1. Test type 48hr Static, non-renewal
2. Salinity 25ppt + 10 percent for all dilutions by
adding dry ocean salts
3. Temperature ( o C) 20 o C + 1 o C or 25 o C + 1 o C, temperature must
not deviate by more than 3 o C during test
4. Light quality Ambient laboratory illumination
5. Photoperiod 16 hour light, 8 hour dark
6. Test chamber size 250 ml (minimum)
7. Test solution volume 200 ml/replicate (minimum)
8. Age of test organisms 1-5 days, < 24 hours age range
9. No. Mysids per test chamber 10
10. No. of replicate test chambers per treatment 4
11. Total no. Mysids per test concentration 40
12. Feeding regime Light feeding using concentrated Artemia
naupli while holding prior to initiating the
test
13. Aeration 2 None
14. Dilution water 5-30 ppt, +/- 10%; Natural seawater, or
deionized water mixed with artificial sea
salts
15. Dilution factor > 0.5
16. Number of dilutions 3 5 plus a control. An additional dilution at
the permitted effluent concentration (%
July 201 2
(updated links/addresses 2023 )
Page 5 of 10
effluent) is required if it is not included in
the dilution series.
17. Effect measured Mortality - no movement of body
appendages on gentle prodding
18. Test acceptability 90% or greater survival of test organisms in
control solution
19. Sampling requirements For on-site tests, samples are used within 24
hours of the time that they are removed from
the sampling device. For off-site tests,
samples must be first used within 36 hours
of collection.
20. Sample volume required Minimum 1 liter for effluents and 2 liters for
receiving waters
Footnotes:
1 Adapted from EPA 821-R-02-012.
2 If dissolved oxygen falls below 4.0 mg/L, aerate at rate of less than 100 bubbles/min.
Routine D.O. checks are recommended.
3 When receiving water is used for dilution, an additional control made up of standard
laboratory dilution water (0% effluent) is required.
Page 6 of 10
EPA NEW ENGLAND TOXICITY TEST CONDITIONS FOR THE INLAND
SILVERSIDE, MENIDIA BERYLLINA 48 HOUR TEST 1
1. Test Type 48 hr Static, non-renewal
2. Salinity 25 ppt + 10 % by adding dry ocean salts
3. Temperature 20 o C + 1 o C or 25 o C + 1 o C, temperature must
not deviate by more than 3 o C during test
4. Light Quality Ambient laboratory illumination
5. Photoperiod 16 hr light, 8 hr dark
6. Size of test vessel 250 mL (minimum)
7. Volume of test solution 200 mL/replicate (minimum)
8. Age of fish 9-14 days; 24 hr age range
9. No. fish per chamber 10 (not to exceed loading limits)
10. No. of replicate test vessels per treatment 4
11. Total no. organisms per concentration 40
12. Feeding regime Light feeding using concentrated Artemia
nauplii while holding prior to initiating the
test
13. Aeration 2 None
14. Dilution water 5-32 ppt, +/- 10% ; Natural seawater, or
deionized water mixed with artificial sea
salts.
15. Dilution factor > 0.5
16. Number of dilutions 3 5 plus a control. An additional dilution at
the permitted concentration (% effluent) is
required if it is not included in the dilution
series.
17. Effect measured
July 2012
(updated links/addresses 2023)
Mortality-no movement on gentle prodding.
July 2012
(updated links/addresses 2023)
Page 7 of 10
18. Test acceptability 90% or greater survival of test organisms in
control solution.
19. Sampling requirements For on-site tests, samples must be used
within 24 hours of the time they are
removed from the sampling device. Off-site
test samples must be used within 36 hours of
collection.
20. Sample volume required Minimum 1 liter for effluents and 2 liters for
receiving waters.
Footnotes:
1 Adapted from EPA 821-R-02-012.
2 If dissolved oxygen falls below 4.0 mg/L, aerate at rate of less than 100 bubbles/min.
Routine D.O. checks recommended.
3 When receiving water is used for dilution, an additional control made up of standard
laboratory dilution water (0% effluent) is required.
V.1. Test Acceptability Criteria
If a test does not meet TAC the test must be repeated with fresh samples within 30 days of the
initial test completion date.
V.2. Use of Reference Toxicity Testing
Reference toxicity test results and applicable control charts must be included in the toxicity
testing report.
In general, if reference toxicity test results fall outside the control limits established by the
laboratory for a specific test endpoint, a reason or reasons for this excursion must be evaluated,
correction made and reference toxicity tests rerun as necessary as prescribed below.
If a test endpoint value exceeds the control limits at a frequency of more than one out of twenty
then causes for the reference toxicity test failure must be examined and if problems are identified
corrective action taken. The reference toxicity test must be repeated during the same month in
which the exceedance occurred.
If two consecutive reference toxicity tests fall outside control limits, the possible cause(s) for the
exceedance must be examined, corrective actions taken and a repeat of the reference toxicity test
must take place immediately. Actions taken to resolve the problem must be reported.
July 2012
(updated links/addresses 2023 )
Page 8 of 10
V.2.a. Use of Concurrent Reference Toxicity Testing
In the case where concurrent reference toxicity testing is required due to a low frequency of
testing with a particular method, if the reference toxicity test results fall slightly outside of
laboratory established control limits, but the primary test met the TAC, the results of the primary
test will be considered acceptable. However, if the results of the concurrent test fall well outside
the established upper control limits i.e. >3 standard deviations for IC25s and LC50 values and >
two concentration intervals for NOECs or NOAECs, and even though the primary test meets
TAC, the primary test will be considered unacceptable and must be repeated.
VI. CHEMICAL ANALYSIS
At the beginning of the static acute test, pH, salinity, and temperature must be measured at the
beginning and end of each 24 hour period in each dilution and in the controls. The following
chemical analyses shall be performed for each sampling event.
Parameter Effluent Diluent
Minimum Level
for effluent *1
(mg/L)
pH x x ---
Salinity x x ppt(o/oo)
Total Residual Chlorine *2 x x 0.02
Total Solids and Suspended Solids x x ---
Ammonia x x 0.1
Total Organic Carbon x x 0.5
Total Metals
Cd x x 0.0005
Pb x x 0.0005
Cu x x 0.003
Zn x x 0.005
Ni x x 0.005
Superscript:
*1 These are the minimum levels for effluent (fresh water) samples. Tests on diluents (marine
waters) shall be conducted using the Part 136 methods that yield the lowest MLs.
*2 Either of the following methods from the 18th Edition of the APHA Standard Methods for the
Examination of Water and Wastewater must be used for these analyses:
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-Method 4500-Cl E Low Level Amperometric Titration (the preferred method);
-Method 4500-CL G DPD Photometric Method.
VII. TOXICITY TEST DATA ANALYSIS
LC50 Median Lethal Concentration
An estimate of the concentration of effluent or toxicant that is lethal to 50% of the test organisms
during the time prescribed by the test method.
Methods of Estimation:
• Probit Method
• Spearman-Karber
• Trimmed Spearman-Karber
• Graphical
See flow chart in Figure 6 on page 73 of EPA 821-R-02-012 for appropriate method to use on a
given data set.
No Observed Acute Effect Level (NOAEL)
See flow chart in Figure 13 on page 87 of EPA 821-R-02-012.
VIII. TOXICITY TEST REPORTING
A report of results must include the following:
• Toxicity Test summary sheet(s) (Attachment F to the DMR Instructions) which includes:
o Facility name
o NPDES permit number
o Outfall number
o Sample type
o Sampling method
o Effluent TRC concentration
o Dilution water used
o Receiving water name and sampling location
o Test type and species
o Test start date
o Effluent concentrations tested (%) and permit limit concentration
o Applicable reference toxicity test date and whether acceptable or not
o Age, age range and source of test organisms used for testing
o Results of TAC review for all applicable controls
o Permit limit and toxicity test results
o Summary of any test sensitivity and concentration response evaluation that was
conducted
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Please note: The NPDES Permit Program Instructions for the Discharge Monitoring
Report Forms (DMRs) are available on EPA’s website at : www.epa.gov/compliance/
discharge-monitoring-reports-avoiding-common-mistakes
In addition to the summary sheets the report must include:
• A brief description of sample collection procedures;
• Chain of custody documentation including names of individuals collecting samples, times
and dates of sample collection, sample locations, requested analysis and lab receipt with
time and date received, lab receipt personnel and condition of samples upon receipt at the
lab(s);
• Reference toxicity test control charts;
• All sample chemical/physical data generated, including minimum levels (MLs) and
analytical methods used;
• All toxicity test raw data including daily ambient test conditions, toxicity test chemistry,
sample dechlorination details as necessary, bench sheets and statistical analysis;
• A discussion of any deviations from test conditions; and
• Any further discussion of reported test results, statistical analysis and concentration-
response relationship and test sensitivity review per species per endpoint.
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ATTACHMENT D
MARINE CHRONIC
TOXICITY TEST PROCEDURE AND PROTOCOL
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I. GENERAL REQUIREMENTS
The permittee shall be responsible for the conduct of acceptable silverside chronic and sea urchin
chronic toxicity tests in accordance with the appropriate test protocols described below:
• Inland Silverside (Menidia beryllina) Larval Growth and Survival Test
• Sea Urchin (Arbacia punctulata) 1 Hour Fertilization Test
Chronic toxicity data shall be reported as outlined in Section VIII.
II. METHODS
The permittee shall use 40 CFR Part 136 methods. Methods and guidance may be found at:
https://www.epa.gov/cwa-methods/whole-effluent-toxicity-methods
The permittee shall also meet the sampling, analysis and reporting requirements included in this
protocol. Where there are conflicting requirements between the Part 136 method and this
protocol, the permittee shall comply with the requirements of the Part 136 method.
III. SAMPLE COLLECTION AND USE
A total of three fresh samples of effluent and receiving water are required for initiation and
subsequent renewals of a marine, chronic, toxicity test. The receiving water control sample must
be collected immediately upstream of the permitted discharge’s zone of influence. Fresh samples
are recommended for use on test days 1, 3, and 5. However, provided a total of three samples
are used for testing over the test period, an alternate sampling schedule is acceptable. The
acceptable holding times until initial use of a fresh sample are 24 and 36 hours for on-site and
off-site testing, respectively. A written waiver is required from the regulating authority for any
hold time extension. All fresh test samples collected may be used for 24, 48 and 72 hour
renewals after initial use. All samples held for use beyond the day of sampling shall be
refrigerated and maintained at a temperature range of 0-6 o C.
If any of the renewal samples are of sufficient potency to cause lethality to 50 percent or more of
the test organisms in any of the test treatments for either species or, if the test fails to meet its
permit limits, then chemical analysis for total metals (originally required for the initial sample
only in Section VI) will be required on the renewal sample(s) as well.
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Sampling guidance dictates that, where appropriate, aliquots for the analysis required in this
protocol shall be split from the samples, containerized and immediately preserved, or analyzed
as per 40 CFR Part 136. EPA approved test methods require that samples collected for metals
analyses be preserved immediately after collection. Testing for the presence of total residual
chlorine (TRC) must be analyzed immediately or as soon as possible, for all effluent samples,
prior to WET testing. For TRC analysis performed on site the results must be included on the
chain of custody (COC) presented to WET laboratory. For the purpose of sample preparation,
i.e. eliminating chlorine prior to toxicity testing, if called for by the permit, TRC analysis may
also be performed by the toxicity testing laboratory and the samples must be dechlorinated, as
necessary, using sodium thiosulfate prior to sample use for toxicity testing. According to
Standard Methods for the Examination of Water and Wastewater describes dechlorination of
samples (APHA, 1992) dechlorination can be achieved using a ratio of 6.7 mg/L anhydrous
sodium thiosulfate to reduce 1 mg/L chlorine.
If dechlorination of a sample by the toxicity testing laboratory is necessary a “sodium
thiosulfate” control, representing the concentration of sodium thiosulfate used to adequately
dechlorinate the sample prior to toxicity testing, must be included in the test.
All samples submitted for chemical and physical analyses will be analyzed according to Section
VI of this protocol. Grab samples must be used for pH, temperature, and total residual oxidants
(as per 40 CFR Part 122.21).
IV. DILUTION WATER
Samples of receiving water must be collected from a location in the receiving water body
immediately upstream of the permitted discharge’s zone of influence at a reasonably accessible
location. Avoid collection near areas of obvious road or agricultural runoff, storm sewers or
other point source discharges and areas where stagnant conditions exist. EPA strongly urges that
screening for toxicity be performed prior to the set up of a full, definitive toxicity test any time
there is a question about the test dilution water's ability to achieve test acceptability criteria
(TAC) as indicated in Section V of this protocol. The test dilution water control response will be
used in the statistical analysis of the toxicity test data. All other control(s) required to be run in
the test will be reported as specified in the Discharge Monitoring Report (DMR) Instructions,
Attachment F, page 2,Test Results & Permit Limits.
The test dilution water must be used to determine whether the test met the applicable test
acceptability criteria (TAC). When receiving water is used for test dilution, an additional control
made up of standard laboratory water (0% effluent) is required. This control will be used to
verify the health of the test organisms and evaluate to what extent, if any, the receiving water
itself is responsible for any toxic response observed.
If the receiving water diluent is found to be, or suspected to be toxic or unreliable, an
alternatedilution water (ADW) of known quality with hardness similar to that of the receiving
water may be substituted. Substitution is species specific meaning that the decision to use ADW
is made for each species and is based on the toxic response of that particular species.
Substitution to an ADW is authorized in two cases. The first is the case where repeating a test
due to toxicity in the site dilution water requires an immediate decision for ADW use be made
by the permittee and toxicity testing laboratory. The second is in the case where two of the
most recent documented incidents of unacceptable site dilution water toxicity requires ADW
use in future WET testing. For the second case, written notification from the permittee
requesting ADW use and written authorization from the permit issuing agency(s) is required
prior to switching to a long-term use of ADW for the duration of the permit.
Written requests for use of ADW with supporting documentation must be sent electronically
to the NPDES Applications Coordinator in EPA Water Division (WD) at the following email
address : R1NPDESReporting@epa.gov
Note: USEPA Region 1 retains the right to modify any part of the alternate dilution water policy
stated in this protocol at any time. Any changes to this policy will be documented in the annual
DMR posting.
See the E PA Region 1 website at https://www.epa.gov/aboutepa/epa-region-1-new-england
(click on NPDES, EPA Permit Attachments, Self-Implementing Alternate Dilution Water
Guidance) for important details on alternate dilution water substitution requests.
If the use of an alternate dilution water (ADW) is authorized, in addition to the ADW test control,
the testing laboratory must, for the purpose of monitoring the receiving water, also run a receiving
water control.
V. TEST CONDITIONS AND TEST ACCEPTABILITY CRITERIA
EPA New England requires that if a reference toxicant test was being performed concurrently with
an effluent or receiving water test and fails, both tests must be repeated.
The following tables summarize the accepted Menidia and Arbacia toxicity test conditions and test
acceptability criteria:
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EPA NEW ENGLAND RECOMMENDED TEST CONDITIONS FOR THE
SEA URCHIN, ARBACIA PUNCTULATA, FERTILIZATION TEST 1
1. Test type Static, non-renewal
2. Salinity 30 o/oo + 2 o/oo by adding dry ocean salts
3. Temperature 20 + 1 o C temperature must
not deviate by more than 3 o C during test
4. Light quality Ambient laboratory illumination
5. Light intensity 10-20 uE/m 2 /s, or 50-100 ft-c (Ambient Laboratory
Levels)
6. Test vessel size Disposal (glass) liquid scintillation vials (20 ml
capacity), presoaked in control water
7. Test solution volume 5 ml
8. Number of sea urchins Pooled sperm from four males and pooled eggs
from four females are used per test
9. Number of egg and sperm cells About 2000 eggs per chamber and 5,000,000
sperm cells per vial
10. Number of replicate chambers 4 per treatment
11. Dilution water Uncontaminated source of natural seawater or
deionized water mixed with artificial sea salts
12. Dilution factor Approximately 0.5, must bracket the permitted
RWC
13. Test duration 1 hour and 20 minutes
14. Effects measured Fertilization of sea urchin eggs
15. Number of treatments per test 2 5 and a control. (receiving water and laboratory
water control) An additional dilution at the
permitted effluent concentration (% effluent) is
required.
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16. Acceptability of test 70% - 90% egg fertilization in all controls.
Minimum of 70% fertilization in dilution water
control. Effluent concentrations exhibiting greater
than 70% fertilization, flagged as statistically
significantly different from the controls, will not be
considered statistically different from the controls
for NOEC reporting.
17. Sampling requirements For on-site tests, samples are to be used within 24
hours of the time that they are removed from the
sampling device. For off-site tests, samples must be
first used within 36 hours of collection.
18. Sample volume required Minimum 1 liter
Footnotes:
1 Adapted from EPA 821-R-02-014
November 2013
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EPA NEW ENGLAND RECOMMENDED TEST CONDITIONS FOR THE INLAND
SILVERSIDE, MENIDIA BERYLLINA, GROWTH AND SURVIVAL TEST 1
______________________________________________________________________________
1. Test type Static, renewal
2. Salinity 5 o/oo to 32 o/oo +/- 2 o/oo of the selected
salinity by adding artificial sea salts
3. Temperature 25 + 1 o C, temperature must
not deviate by more than 3 o C during test
4. Light quality Ambient laboratory light
5. Light intensity 10-20 uE/m 2 /s, or 50-100 ft-C
(Ambient Laboratory Levels)
6. Photoperiod 16 hr light, 8 hr darkness
7. Test vessel size 600 - 1000 mL beakers or equivalent (glass test
chambers should be used)
8. Test solution volume 500-750 mL/replicate loading and DO restrictions
must be met)
9. Renewal of test solutions Daily using most recently collected sample
10. Age of test organisms Seven to eleven days post hatch; 24 hr range in age
11. Larvae/test chamber 15 (minimum of 10)
12. Number of replicate chambers 4 per treatment
13. Source of food Newly hatched and rinsed Artemia nauplii less than
24 hr old
14. Feeding regime Feed once a day 0.10 g wet wt Artemia nauplii per
replicate on days 0 – 2 feed 0.15 g wet wt Artemia
nauplii per replicate on days 3-6
15. Cleaning Siphon daily, immediately before test solution
renewal and feeding
16. Aeration 2 None
17. Dilution water Uncontaminated source of natural seawater; or
deionized water mixed with artificial sea salts
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18. Effluent concentrations 5 and a control (receiving water and laboratory
water control) An additional dilution at the
permitted effluent concentration (% effluent) is
required
19. Dilution factor > 0.5, must bracket the permitted RWC
20. Test duration 7 days
21. Effects measured Survival and growth (weight)
22. Acceptability of test The average survival of dilution water control
larvae is a minimum of 80%, and the average dry wt
of unpreserved control larvae is a minimum of 0.5
mg, or the average dry wt of preserved control
larvae is a minimum of 0.43 mg if preserved not
more than 7 days in 4% formalin or 70% ethanol
23. Sampling requirements For on-site tests, samples are collected daily and
used within 24 hours of the time they are removed
from the sampling device. For off-site tests, sam-
ples must be first used within 36 hours of collection.
24. Sample Volume Required Minimum of 6 liters/day.
______________________________________________________________________________
Footnotes:
1 Adapted from EPA 821-R-02-014
2 If dissolved oxygen (D.O.) falls below 4.0 mg/L, aerate all chambers at a rate of less than
100 bubbles/min. Routine D.O. checks are recommended.
November 2013
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V.1. Test Acceptability Criteria
If a test does not meet TAC the test must be repeated with fresh samples within 30 days of the
initial test completion date.
V.2. Use of Reference Toxicity Testing
Reference toxicity test results and applicable control charts must be included in the toxicity
testing report.
In general, if reference toxicity test results fall outside the control limits established by the
laboratory for a specific test endpoint, a reason or reasons for this excursion must be evaluated,
correction made and reference toxicity tests rerun as necessary as prescribed below.
If a test endpoint value exceeds the control limits at a frequency of more than one out of twenty
then causes for the reference toxicity test failure must be examined and if problems are identified
corrective action taken. The reference toxicity test must be repeated during the same month in
which the exceedance occurred.
If two consecutive reference toxicity tests fall outside control limits, the possible cause(s) for the
exceedance must be examined, corrective actions taken and a repeat of the reference toxicity test
must take place immediately. Actions taken to resolve the problem must be reported.
V.2.a. Use of Concurrent Reference Toxicity Testing
In the case where concurrent reference toxicity testing is required due to a low frequency of
testing with a particular method, if the reference toxicity test results fall slightly outside of
laboratory established control limits, but the primary test met the TAC, the results of the primary
test will be considered acceptable. However, if the results of the concurrent test fall well outside
the established upper control limits i.e. >3 standard deviations for IC25s values and > two
concentration intervals for NOECs, and even though the primary test meets TAC, the primary
test will be considered unacceptable and must be repeated.
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VI. CHEMICAL ANALYSIS
The toxicity test requires measurement of pH, salinity, and temperature at the beginning and end
of each 24 hour period in each dilution and controls for both daily test renewal and waste. The
following chemical analyses shall be performed for each initial sample as well as any renewal
samples, if necessary pursuant to the requirement of Part III above.
Parameter Effluent Diluent
Minimum Level
for effluent *1
(mg/L)
pH x x ---
Salinity x x ppt(o/oo)
Total Residual Chlorine *2 x x 0.02
Total Solids and Suspended Solids x x ---
Ammonia x x 0.1
Total Organic Carbon x x 0.5
Total Metals
Cd x x 0.0005
Pb x x 0.0005
Cu x x 0.003
Zn x x 0.005
Ni x x 0.005
Superscript:
*1 These are the minimum levels for effluent (fresh water) samples. Tests on diluents (marine
waters) shall be conducted using the Part 136 methods that yield the lowest MLs.
*2 Either of the following methods from the 18th Edition of the APHA Standard Methods for the
Examination of Water and Wastewater must be used for these analyses:
-Method 4500-Cl E Low Level Amperometric Titration (the preferred method);
-Method 4500-CL G DPD Photometric Method.
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VII. TOXICITY TEST DATA ANALYSIS AND REVIEW
A. Test Review
1. Concentration / Response Relationship
A concentration/response relationship evaluation is required for test endpoint determinations
from both Hypothesis Testing and Point Estimate techniques. The test report is to include
documentation of this evaluation in support of the endpoint values reported.
The dose-response review must be performed as required in Section 10.2.6 of EPA-821-
R-02-014. Guidance for this review can be found at :
https://www.epa.gov/cwa-methods/whole-effluent-toxicity-methods
In most cases, the review will result in one of the following three conclusions: (1) Results are
reliable and reportable; (2) Results are anomalous and require explanation; or (3) Results are
inconclusive and a retest with fresh samples is required.
2. Test Variability (Test Sensitivity)
This review step is separate from the determination of whether a test meets or does not meet
TAC. Within test variability is to be examined for the purpose of evaluating test sensitivity. This
evaluation is to be performed for the sub-lethal hypothesis testing endpoint growth for Menidia
beryllina as required by the permit. The test report is to include documentation of this evaluation
to support that the endpoint values reported resulted from a toxicity test of adequate sensitivity.
This evaluation must be performed as required in Section 10.2.8 of EPA-821-R-02-014.
To determine the adequacy of test sensitivity, USEPA requires the calculation of test percent
minimum significant difference (PMSD) values. In cases where NOEC determinations are made
based on a non-parametric technique, calculation of a test PMSD value, for the sole purpose of
assessing test sensitivity, shall be calculated using a comparable parametric statistical analysis
technique. The calculated test PMSD is then compared to the upper and lower PMSD bounds
shown for marine tests in Section 10.2.8.3, p. 54, Table 6 of EPA-821-R-02-014. The
comparison will yield one of the following determinations.
• The test PMSD exceeds the PMSD upper bound test variability criterion in Table 6, the test
results are considered highly variable and the test may not be sensitive enough to determine
the presence of toxicity at the permit limit concentration (PLC). If the test results indicate
that the discharge is not toxic at the PLC, then the test is considered insufficiently sensitive
and must be repeated within 30 days of the initial test completion using fresh samples. If the
test results indicate that the discharge is toxic at the PLC, the test is considered acceptable
and does not have to be repeated.
• The test PMSD falls below the PMSD lower bound test variability criterion in Table 6, the
test is determined to be very sensitive. In order to determine which treatment(s) are
statistically significant and which are not, for the purpose of reporting a NOEC, the relative
percent difference (RPD) between the control and each treatment must be calculated and
compared to the lower PMSD boundary. See Understanding and Accounting for Method
Variability in Whole Effluent Toxicity Applications Under the NPDES Program , EPA 833-
R-003, June 2000, Section 6.4.2. This document can be located under Guidance
Documents at the following USEPA website location :
https://www.epa.gov/aboutepa/epa-region-1-new-england
(click on NPDES, EPA Permit Attachments)
If the RPD for a treatment falls below the PMSD lower bound, the difference is
considered statistically insignificant. If the RPD for a treatment is greater that the
PMSD lower bound, then the treatment is considered statistically significant.
• The test PMSD falls within the PMSD upper and lower bounds in Table 6, the sub-lethal test
endpoint values shall be reported as is.
B. Statistical Analysis
__________________
1. General - Recommended Statistical Analysis Method
Refer to general data analysis flowchart, EPA 821-R-02-014, page 45
For discussion on Hypothesis Testing, refer to EPA 821-R-02-014, Section 9.6
For discussion on Point Estimation Techniques, refer to EPA 821-R-02-014, Section 9.7
2. Menidia beryllina
Refer to survival hypothesis testing analysis flowchart, EPA 821-R-02-014, page 181
Refer to survival point estimate techniques flowchart, EPA 821-R-02-013, page 182
Refer to growth data statistical analysis flowchart, EPA 821-R-02-014, page 193
3. Arbacia punctulata
Refer to fertilization data testing flowchart, EPA 821-R-02-014, page
312
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VIII. TOXICITY TEST REPORTING
A report of results must include the following:
• Toxicity Test summary sheet(s) (Attachment F to the DMR Instructions) which includes:
o Facility name
o NPDES permit number
o Outfall number
o Sample type
o Sampling method
o Effluent TRC concentration
o Dilution water used
o Receiving water name and sampling location
o Test type and species
o Test start date
o Effluent concentrations tested (%) and permit limit concentration
o Applicable reference toxicity test date and whether acceptable or not
o Age, age range and source of test organisms used for testing
o Results of TAC review for all applicable controls
o Test sensitivity evaluation results (test PMSD for growth )
o Permit limit and toxicity test results
o Summary of test sensitivity and concentration response evaluation
Please note: The NPDES Permit Program Instructions for the Discharge Monitoring
Report Forms (DMRs) are available on EPA’s website at :
www.epa.gov/compliance/discharge-monitoring-reports-avoiding-common-mistakes
In addition to the summary sheets the report must include:
• A brief description of sample collection procedures;
• Chain of custody documentation including names of individuals collecting samples, times
and dates of sample collection, sample locations, requested analysis and lab receipt with
time and date received, lab receipt personnel and condition of samples upon receipt at the
lab(s);
• Reference toxicity test control charts;
• All sample chemical/physical data generated, including minimum limits (MLs) and
analytical methods used;
• All toxicity test raw data including daily ambient test conditions, toxicity test chemistry,
sample dechlorination details as necessary, bench sheets and statistical analysis;
• A discussion of any deviations from test conditions; and
• Any further discussion of reported test results, statistical analysis and concentration-
response relationship and test sensitivity review.
ATTACHMENT E
USEPA REGION 1 FRESHWATER ACUTE
TOXICITY TEST PROCEDURE AND PROTOCOL
February 28, 2011
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1
I. GENERAL REQUIREMENTS
The permittee shall conduct acceptable acute toxicity tests in accordance with the appropriate
test protocols described below:
• Daphnid (Ceriodaphnia dubia) definitive 48 hour test.
• Fathead Minnow (Pimephales promelas) definitive 48 hour test.
II. METHODS
Acute toxicity test data shall be reported as outlined in Section VIII.
The permittee shall use 40 CFR Part 136 methods. Methods and guidance may be found at:
https://www.epa.gov/cwa-methods/whole-effluent-toxicity-methods
The permittee shall also meet the sampling, analysis and reporting requirements included in this
protocol. This protocol defines more specific requirements while still being consistent with the
Part 136 methods. If, due to modifications of Part 136, there are conflicting requirements
between the Part 136 method and this protocol, the permittee shall comply with the requirements
of the Part 136 method.
III. SAMPLE COLLECTION
A discharge sample shall be collected. Aliquots shall be split from the sample, containerized
and preserved (as per 40 CFR Part 136) for chemical and physical analyses required. The
remaining sample shall be measured for total residual chlorine and dechlorinated (if detected) in
the laboratory using sodium thiosulfate for subsequent toxicity testing. (Note that EPA
approved test methods require that samples collected for metals analyses be preserved
immediately after collection.) Grab samples must be used for pH, temperature, and total
residual chlorine (as per 40 CFR Part 122.21).
Standard Methods for the Examination of Water and Wastewater describes dechlorination of
samples (APHA, 1992). Dechlorination can be achieved using a ratio of 6.7 mg/L anhydrous
sodium thiosulfate to reduce 1.0 mg/L chlorine. If dechlorination is necessary, a thiosulfate
control (maximum amount of thiosulfate in lab control or receiving water) must also be run in
the WET test.
All samples held overnight shall be refrigerated at 1- 6 o C.
IV. DILUTION WATER
A grab sample of dilution water used for acute toxicity testing shall be collected from the
receiving water at a point immediately upstream of the permitted discharge’s zone of influence at
a reasonably accessible location. Avoid collection near areas of obvious road or agricultural
runoff, storm sewers or other point source discharges and areas where stagnant conditions exist.
In the case where an alternate dilution water has been agreed upon an additional receiving water
control (0% effluent) must also be tested.
If the receiving water diluent is found to be, or suspected to be toxic or unreliable, an alternate
standard dilution water of known quality with a hardness, pH, conductivity, alkalinity, organic
carbon, and total suspended solids similar to that of the receiving water may be substituted
AFTER RECEIVING WRITTEN APPROVAL FROM THE PERMIT ISSUING
AGENCY(S) .
Written requests for use of ADW with supporting documentation must be sent electronically to
the NPDES Applications Coordinator in EPA Water Division (WD) at the following email
address:
R1NPDESReporting@epa.gov
Note: USEPA Region 1 retains the right to modify any part of the alternate dilution water
policy stated in this protocol at any time. Any changes to this policy will be documented in the
annual DMR posting.
See the EPA Region 1 website at https://www.epa.gov/aboutepa/epa-region-1-new-england
(click on NPDES, EPA Permit Attachments, Self-Implementing Alternate Dilution Water
Guidance) for important details on alternate dilution water substitution requests.
February 28, 2011
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3
EPA NEW ENGLAND EFFLUENT TOXICITY TEST CONDITIONS FOR THE
DAPHNID, CERIODAPHNIA DUBIA 48 HOUR ACUTE TESTS 1
1. Test type Static, non-renewal
2. Temperature ( o C) 20 + 1 o C or 25 + 1 o C
3. Light quality Ambient laboratory illumination
4. Photoperiod 16 hour light, 8 hour dark
5. Test chamber size Minimum 30 ml
6. Test solution volume Minimum 15 ml
7. Age of test organisms 1-24 hours (neonates)
8. No. of daphnids per test chamber 5
9. No. of replicate test chambers
per treatment
4
10. Total no. daphnids per test
concentration
20
11. Feeding regime As per manual, lightly feed YCT and
Selenastrum to newly released organisms
while holding prior to initiating test
12. Aeration None
13. Dilution water 2 Receiving water, other surface water,
synthetic water adjusted to the hardness and
alkalinity of the receiving water (prepared
using either Millipore Milli-Q R or
equivalent deionized water and reagent
grade chemicals according to EPA acute
toxicity test manual) or deionized water
combined with mineral water to appropriate
hardness.
14. Dilution series > 0.5, must bracket the permitted RWC
15. Number of dilutions 5 plus receiving water and laboratory water
control and thiosulfate control, as
necessary. An additional dilution at the
permitted effluent concentration (%
effluent) is required if it is not included in
the dilution series.
February 28, 2011
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February 28, 2011
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4
16. Effect measured Mortality-no movement of body
or appendages on gentle prodding
17. Test acceptability 90% or greater survival of test organisms in
dilution water control solution
18. Sampling requirements For on-site tests, samples must be used
within 24 hours of the time that they are
removed from the sampling device. For off-
site tests, samples must first be used within
36 hours of collection.
19. Sample volume required Minimum 1 liter
Footnotes:
1. Adapted from EPA-821-R-02-012.
2. Standard prepared dilution water must have hardness requirements to generally reflect the
characteristics of the receiving water.
EPA NEW ENGLAND TEST CONDITIONS FOR THE FATHEAD MINNOW
(PIMEPHALES PROMELAS) 48 HOUR ACUTE TEST 1
1. Test Type Static, non-renewal
2. Temperature ( o C) 20 + 1 o C or 25 + 1 o C
3. Light quality Ambient laboratory illumination
4. Photoperiod 16 hr light, 8 hr dark
5. Size of test vessels 250 mL minimum
6. Volume of test solution Minimum 200 mL/replicate
7. Age of fish 1-14 days old and age within 24 hrs of each
other
8. No. of fish per chamber 10
9. No. of replicate test vessels
per treatment
4
10. Total no. organisms per
concentration
40
11. Feeding regime As per manual, lightly feed test age larvae
using concentrated brine shrimp nauplii
while holding prior to initiating test
12. Aeration None, unless dissolved oxygen (D.O.)
concentration falls below 4.0 mg/L, at which
time gentle single bubble aeration should be
started at a rate of less than 100
bubbles/min. (Routine D.O. check is
recommended.)
13. dilution water 2 Receiving water, other surface water,
synthetic water adjusted to the hardness and
alkalinity of the receiving water (prepared
using either Millipore Milli-Q R or equivalent
deionized and reagent grade chemicals
according to EPA acute toxicity test manual)
or deionized water combined with mineral
water to appropriate hardness.
1 4. Dilution series > 0.5, must bracket the permitted RWC
February 28, 2011 5
(updated links/addresses 2023)
February 28, 2011
( updated links/addresses 2023 )
6
15. Number of dilutions 3 5 plus receiving water and laboratory water
control and thiosulfate control, as necessary.
An additional dilution at the permitted
effluent concentration (% effluent) is
required if it is not included in the dilution
series.
16. Effect measured Mortality-no movement on gentle prodding
17. Test acceptability 90% or greater survival of test organisms in
dilution water control solution
18. Sampling requirements For on-site tests, samples must be used
within 24 hours of the time that they are
removed from the sampling device. For off-
site tests, samples are used within 36 hours
of collection.
19. Sample volume required Minimum 2 liters
Footnotes:
1. Adapted from EPA-821-R-02-012
2. Standard dilution water must have hardness requirements to generally reflect
characteristics of the receiving water.
February 28, 2011
( updated links/addresses 2023 )
7
VI. CHEMICAL ANALYSIS
At the beginning of a static acute toxicity test, pH, conductivity, total residual chlorine, oxygen,
hardness, alkalinity and temperature must be measured in the highest effluent concentration and
the dilution water. Dissolved oxygen, pH and temperature are also measured at 24 and 48 hour
intervals in all dilutions. The following chemical analyses shall be performed on the 100
percent effluent sample and the upstream water sample for each sampling event.
Parameter Effluent Receiving
Water
ML (mg/l)
Hardness 1 x x 0.5
Total Residual Chlorine (TRC) 2, 3 x 0.02
Alk - alinity x x 2.0
pH x x --
Specific Conductance x x --
Total Solids x --
Total Dissolved Solids x --
Ammonia x x 0.1
Total Organic Carbon x x 0.5
Total Metals
Cd x x 0.0005
Pb x x 0.0005
Cu x x 0.003
Zn x x 0.005
Ni x x 0.005
Al x x 0.02
Other as permit requires
Notes:
1. Hardness may be determined by:
• APHA Standard Methods for the Examination of Water and Wastewater , 21st
Edition
- Method 2340B (hardness by calculation)
- Method 2340C (titration)
2. Total Residual Chlorine may be performed using any of the following methods provided the
required minimum limit (ML) is met.
• APHA Standard Methods for the Examination of Water and Wastewater , 21st
Edition
- Method 4500-CL E Low Level Amperometric Titration
- Method 4500-CL G DPD Colorimetric Method
3. Required to be performed on the sample used for WET testing prior to its use for
toxicity testing.
February 28, 2011
( updated links/addresses 2023 )
8
VII. TOXICITY TEST DATA ANALYSIS
LC50 Median Lethal Concentration (Determined at 48 Hours)
Methods of Estimation:
• Probit Method
• Spearman-Karber
• Trimmed Spearman-Karber
• Graphical
See the flow chart in Figure 6 on p. 73 of EPA-821-R-02-012 for appropriate method to use on a
given data set.
No Observed Acute Effect Level (NOAEL)
See the flow chart in Figure 13 on p. 87 of EPA-821-R-02-012.
VIII. TOXICITY TEST REPORTING
A report of the results will include the following:
• Description of sample collection procedures, site description
• Names of individuals collecting and transporting samples, times and dates of sample
collection and analysis on chain-of-custody
• General description of tests: age of test organisms, origin, dates and results of standard
toxicant tests; light and temperature regime; other information on test conditions if
different than procedures recommended. Reference toxicant test data should be included.
• All chemical/physical data generated. (Include minimum detection levels and minimum
quantification levels.)
• Raw data and bench sheets.
• Provide a description of dechlorination procedures (as applicable).
• Any other observations or test conditions affecting test outcome.
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 1 of 9
EPA - New England
Reassessment of Technically Based Industrial Discharge Limits
Under 40 CFR §122.210)(4), all Publicly Owned Treatment Works (POTWs) with approved
Industrial Pretreatment Programs (IPPs) shall provide the following infonnation to the Director: a
written evaluation of the need to revise local industrial discharge limits under 40 CFR
§403.5(c)(l).
Below is a fonn designed by the U.S. Environmental Protection Agency (EPA - New England) to
assist POTWs with approved IPPs in evaluating whether their existing Technically Based Local
Limits (TBLLs) need to be recalculated. The fonn allows the permittee and EPA to evaluate and
compare pertinent infonnation used in previous TBLLs calculations against present conditions at
thePOTW.
Please read direction below before filling out form.
ITEM I.
* In Column (I), list what your POTW's influent flow rate was when your existing TBLLs
were calculated. In Column (2), list your POTW's present influent flow rate. Your
current flow rate should be calculated using the POTW's average daily flow rate from the
previous 12 months.
* In Column (1) list what your POTW's SIU flow rate was when your existing TBLLs were
calculated. In Column (2), list your POTW's present SIUflow rate.
* In Column (I), list what dilution ratio and/or 7Q10 value was used in your old/expired
NPDES pennit In Column (2), list what dilution ration and/or 7QI0 value is presently
being used in your new/reissued NPDES permit.
The 7Q10 value is the lowest seven day average flow rate, in the river, over a ten year
period. The 7QI0 value and/or dilution ratio used by EPA in your new NPDES pennit
can be found in yourNPDES permit "Fact Sheet."
* In Column (l), list the safety factor, if any, that was used when your existing TBLLs were
calculated.
* In Column()), note how your bio-solids were managed when your existing TBLLs were
calculated. In Column (2), note how your POTW is presently disposing of its biosolids
and how your POTW will be disposing of its biosolids in the future.
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 2 of 9
ITEM II.
* List what your existing TBLLs are - as they appear in your current Sewer Use Ordinance
(SUO).
ITEMIII.
* Identify how your existing TBLLs are allocated out to your industrial community. Some
pollutants may be allocated differently than others, if so please explain.
ITEM IV.
* Since your existing TBLLs were calculated, identify the following in detail:
(1) if your POTW has experienced any upsets, inhibition, interference or pass-through
as a result of an industrial discharge.
(2) if your POTW is presently violating any of its current NPDES pennit limitations -
include toxicity.
ITEMV.
* Using current sampling data, list in Column ()) the average and maximum amount of
pollutants (in pounds·per day) received in the POTW's influent. Current sampling data is
defined as data obtained over the last 24 month period.
All influent data collected and analyzed must be in accordance with 40 CFR §136.
Sampling data collected should be analyzed using the lowest possible detection method(s),
e.g. graphite furnace.
* Based on your existing TBLLs, as presented in Item 11., list in Column (2), for each
pollutant the Maximum Allowable Headwork Loading (MAHL) values derived from an
applicable environmental criteria or standard, e.g. water quality, sludge, NPDES,
inhibition, etc. For more infonnation, please see EPA's Local Limit Guidance Document
(July 2004).
Item VI.
* Using current sampling data, list in Column (1) the average and maximum amount of
pollutants (in micrograms per liter) present your POTW's effluent. Current sampling data
is defined as data obtained during the last 24 month period.
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 3 of 9
(Item VI. continued)
All effluent data collected and analyzed must be in accordance with 40 CFR §136.
Sampling data collected should be analyzed using the lowest possible detection method(s),
e.g. graphite furnace.
* List in Column (2A) what the Water Quality Standards (WQS) were (in micrograms per
liter) when your TBLLs were calculated, please note what hardness value was used at that
time. Hardness should be expressed in milligram per liter of Calcium Carbonate.
List in Column (2B) the current WQSs or "Chronic Gold Book" values for each pollutant
multiplied by the dilution ratio used in your new/reissued NPDES permit. For example,
with a dilution ratio of 25:1 at a hardness of25 mg/1- Calcium Carbonate (copper's chronic
WQS equals 6.54 ug/1) the chronic NPDES pennit limit for copper would equal 156.25
ug/1.
ITEM VII.
* In Column (1), list all pollutants (in micrograms per liter) limited in your new/reissued
NPDES permit. In Column (2), list all pollutants limited in your old/expired NPDES
pennit.
ITEM VIII.
* Using current sampling data, list in Column (I) the average and maximum amount of
pollutants in your POTW's biosolids. Current data is defined as data obtained during the
last 24 month period. Results are to be expressed as total dry weight.
All biosolids data collected and analyzed must be in accordance with 40 CFR §136.
In Column (2A), list current State and/or Federal sludge standards that your facility's
biosolids must comply with. Also note how your POTW currently manages the disposal
of its biosolids. If your POTW is planing on managing its biosolids differently, list in
Column (2B) what your new biosolids criteria will be and method of disposal.
In general, please be sure the units reported are correct and all pertinent information is included
in your evaluation. If you have any questions, please contact your pretreatment representative at
EPA - New England.
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 4 of 9
REASSESSMENT OF TECHNICALLY BASED LOCAL LIMITS
(TBLLs)
POTW Name & Address :
NPDES PERMIT #
Date EPA approved current TBLLs: _
Date EPA approved current Sewer Use Ordinance
ITEM I.
In Column (1) list the conditions that existed when your current TBLLs were calculated. In
Column (2), list current conditions or expected conditions at your POTW.
Column (1)
EXISTING TBLLs
Column (2)
PRESENT CONDITIONS
POTW Flow (MGD)
Dilution Ratio or 7QIO
(from NPDES Permit)
SIU Flow (MGD)
Safety Factor NIA
Biosolids Disposal
Method(s)
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 5 of 9
ITEMll.
EXISTING TBLLs
POLLUTANT NUMERlCAL
LIMIT
(mg/]) or (lb/day)
POLLUTANT NUMERICAL
LIMIT
(mg/I) or (lb/day)
ITEM ill.
Note how your existing TBLLs, listed in Item II., are allocated to your Significant Industrial
Users (SlUs), i.e. unifonn concentration, contributory flow, mass proportioning, other. Please
specify by circling.
ITEM IV.
Has your POTW experienced any upsets, inhibition, interference or pass-through from industrial
sources since your existing TBLLs were calculated?
If yes, explain.
H s your POTW violated any of its NPDES permit limits and/or toxicity test requirements?
If yes, explain.
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 6 of 9
ITEMV.
Using current POTW influent sampling data fill in Column (1). In Column (2), list your
Maximum Allowable Headwork Loading (MAHL) values used to derive your TBLLs listed in
Item II. In addition, please note the Environmental Criteria for which each MAHL value was
established, i.e. water quality, sludge, NPDES etc.
Pollutant Column (I)
Influent Data Analyses
Maximum Average
(lb/day)
(lb/da
y)
Column (2)
MAHL Values Criteria
(lb/day)
Arsenic
Cadmium
Chromium
Copper
Cyanide
Lead
Mercury
Nickel
Silver
Zinc
Other (List)
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 7 of 9
ITEMVI.
Using current POTW effluent sampling data, fill in Column (1). In Column (2A) list what
the Water Quality Standards (Gold Book Criteria) were at the time your existing TBLLs were
developed. List in Column (2B) current Gold Book values multiplied by the dilution ratio
used in your new/reissued NPDES permit.
Pollutant Column (1)
Effluent Data Analyses
Maximum Average
(ug/1) (ug/1)
Columns
{2A)
(2B)
Water Quality Criteria
(Gold Book)
From TBLLs
Today
(ug/1)
(ug/1)
Arsenic
*Cadmium
*Chromium
*Copper
Cyanide
*Lead
Mercury
*Nickel
Silver
*Zinc
Other (List)
*Hardness Dependent (mg/I - CaC03)
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 8 of 9
ITEMVII.
In Column (1), identify all pollutants limited in your new/reissued NPDES permit. In
Column (2), identify all pollutants that were limited in your old/expired NPDES permit.
Column (1) Column (2)
NEW PERMIT
Pollutants
Limitations
Pollutants
OLD PERMIT
(ug/1)
Limitations
(ug/1)
Draft Permit NPDES Permit No. MA0103284
202 3 Reissuance
Attachment F: Reassessment of TBIDL
Page 9 of 9
ITEM VIII.
Using current POTW biosolids data, fill in Column (1). In Column (2A), list the biosolids
criteria that was used at the time your existing TBLLs were calculated. If your POTW is
planing on managing its biosolids differently, list in Column (2B) what your new biosolids
criteria would be and method of disposal.
Pollutant
Column (1)
Data Analyses
Biosolids
Columns
(2A)
(2B)
Biosolids Criteria
From TBLLs
Average New
(mg/kg)
(mg/kg) (mg/kg)
Arsenic
Cadmium
Chromium
Copper
Cyanide
Lead
Mercury
Nickel
Silver
Zinc
Molybdenum
Selenium
Other (List)
Draft Permit No. MA0103284
202 3 Reissuance
Attachment G: Industrial Pretreatment Report
Page 1 of 4
Industrial Pretreatment Program Annual Report
The Permittee shall provide to the Approval Authority with an annual report that briefly
describes the POTW's program activities, including activities of all participating agencies, if
more than one jurisdiction is involved in the local program. The report required by this
section shall be submitted no later than one year after approval of the POTW's Pretreatment
Program, and at least annually thereafter, and must include, at a minimum, the applicable
required data in appendix A to 40 CFR part 127. The report required by this section must also
include a summary of changes to the POTW's pretreatment program that have not been
previously reported to the Approval Authority and any other relevant information requested
by the Approval Authority . As of December 21, 2025 all annual reports submitted in
compliance with this section must be submitted electronically by the POTW Pretreatment
Program to the Approval Authority or initial recipient, as defined in 40 CFR 127.2(b) , in
compliance with this section and 40 CFR part 3 (including, in all cases, subpart D to part 3),
40 CFR 122.22 , and 40 CFR part 127. Part 127 is not intended to undo existing requirements
for electronic reporting. Prior to this date, and independent of part 127, the Approval
Authority may also require POTW Pretreatment Programs to electronically submit annual
reports under this section if specified by a particular permit or if required to do so by state
law.
The permitted shall submit to Approval Authority and the state permitting authority a report
that contains the following information requested by EPA:
1. An updated list of the POTW's Industrial Users by category as set forth in 40 C.F.R.
403.8(f)(2)(i), to include:
a. Names and addresses, or a list of deletions and additions keyed to a previously
submitted list. The POTW shall provide a brief explanation of each deletion.
This list shall identify which Industrial Users are subject to categorical
Pretreatment Standards and specify which Standards are applicable to each
Industrial User . The list shall indicate which Industrial Users are subject to
local standards that are more stringent than the categorical Pretreatment
Standards. The POTW shall also list the Industrial Users that are subject only
to local Requirements. The list must also identify Industrial Users subject to
categorical Pretreatment Standards that are subject to reduced reporting
requirements under paragraph (e)(3), and identify which Industrial Users are
Non-Significant Categorical Industrial Users .
b. Permit status. Whether each SIU has an unexpired control mechanism and an
explanation as to why any SIUs are operating without a current, unexpired
control mechanism (e.g. permit);
c. Baseline monitoring reporting requirements for newly promulgated industries
d. In addition, a brief description of the industry and general activities;
Draft Permit No. MA0103284
202 3 Reissuance
Attachment G: Industrial Pretreatment Report
Page 1 of 4
2. A summary of compliance and enforcement activities during the preceding year,
including the number of:
a. significant industrial users inspected by POTW (include inspection dates for each
industrial user),
b. significant industrial users sampled by POTW (include sampling dates for
each industrial user),
c. compliance schedules issued (include list of subject users),
d. written notices of violations issued (include list of subject users),
e. administrative orders issued (include list of subject users),
f. criminal or civil suits filed (include list of subject users) and,
g. penalties obtained (include list of subject users and penalty amounts);
3. A narrative description of program effectiveness including present and proposed changes
to the program, such as funding, staffing, ordinances, regulations, rules and/or statutory
authority;
4. The Permittee shall prepare annually a list of industrial users, which during the preceding
twelve (12) months have significantly violated Pretreatment Standards or requirements 40
C.F.R. 403.8(f)(2)(vii). This list is to be published annually in a newspaper of general
circulation in the Permittee's service area.
5. A summary of all monitoring activities performed within the previous twelve (12)
months. The following information shall be reported:
Total number of SIUs inspected; and
Total number of SIUs sampled.
a. For all industrial users that were in Significant Non-Compliance during the
previous twelve (12) months, provide the name of the violating industrial user;
indicate the nature of the violations, the type and number of actions taken
(administrative order, criminal or civil suit, fines or penalties collected, etc.) and
current compliance status. Indicate if the company returned to compliance and
the date compliance was attained. Determination of Significant Non-Compliance
shall be performed.
6. A summary of all enforcement actions not covered by the paragraph above conducted in
accordance with the approved Enforcement Response Plan.
7. A description of actions being taken to reduce the incidence of significant violations by
significant industrial users.
8. A detailed description of all interference and pass-through that occurred during the past
year.
9. A thorough description of all investigations into interference and pass-through during the
past year.
10. A description of monitoring, sewer inspections and evaluations which were done during
the past year to detect interference and pass-through, specifying parameters and
Draft Permit No. MA0103284
202 3 Reissuance
Attachment G: Industrial Pretreatment Report
Page 1 of 4
frequencies;
11. The Permittee shall analyze the treatment facility influent and effluent at least
Annually for the presence of the toxic pollutants listed in 40 CFR Part 122
Appendix D (NPDES Application Testing Requirements) Table III as follows:
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Cyanide
Phenols
The sampling program shall consist of one 24-hour flow-proportioned composite and at
least one grab sample that is representative of the flows received by the POTW. The
composite shall consist of hourly flow-proportioned grab samples taken over a 24-hour
period if the sample is collected manually or shall consist of a minimum of 48 samples
collected at 30 minute intervals if an automated sampler is used. Cyanide shall be taken
as a grab sample during the same period as the composite sample. Sampling and
preservation shall be consistent with 40 CFR Part 136. All analytical procedures and
method detection limits must be specified when reporting the results of such analyses.
12. The Permittee shall analyze the treatment facility sludge (biosolids) prior to disposal, for
the presence of toxic pollutants listed above in 40 CFR 122 Appendix D (NPDES
Draft Permit No. MA0103284
202 3 Reissuance
Attachment G: Industrial Pretreatment Report
Page 1 of 4
Application Testing Requirements) Table III at least once per year. If the Permittee does
not dispose of biosolids during the calendar year, the Permittee shall certify to that in the
Pretreatment Annual Report and the monitoring requirements in this paragraph shall be
suspended for that calendar year.
a. The Permittee shall use sample collection and analysis procedures as approved for use
under 40 CFR Part 503 or specified in the EPA Region 8 General Permit for biosolids.
13. The summary shall include an evaluation of influent sampling results versus
threshold inhibitory concentrations for the Wastewater Treatment System and
effluent sampling results versus water quality standards. Such a comparison shall
be based on the sampling program described in the paragraphs above or any
similar sampling program described in this Permit.
14. Identification of the specific locations, if any, designated by the Permittee for receipt
(discharge) of trucked or hauled waste, if modified;
15. Information as required by the Approval Authority or state permitting authority on the
discharge to the POTW from the following activities:
(A) Ground water clean-up from underground storage tanks;
(B) Trucked or hauled waste; and,
(C) Groundwater clean-up from RCRA or Superfund sites.
16. A description of all changes made during the previous calendar year to the Permittee's
pretreatment program that were not submitted as substantial or non substantial
modifications to EPA.
17. The date of the latest adoption of local limits and an indication as to whether or not the
Town is under a State or Federal compliance schedule that includes steps to be taken to
revise local limits.
18. Results of all PFAS sampling conducted of industrial sectors in accordance with Section
E.7 (if applicable) of the NPDES permit of the following pollutants:
PFAS Analytes per Draft Method 1633
19. Any other information that may be deemed necessary by the Approval Authority.
NPDES Permit No. MA0103284
202 3 Reissuance
Appendix H: PFAS Analyte List
Page 1 of 2
Target Analyte Name Abbreviation CAS Number
Perfluoroalkyl carboxylic acids
Perfluorobutanoic acid PFBA 375-22-4
Perfluoropentanoic acid PFPeA 2706-90-3
Perfluorohexanoic acid PFHxA 307-24-4
Perfluoroheptanoic acid PFHpA 375-85-9
Perfluorooctanoic acid PFOA 335-67-1
Perfluorononanoic acid PFNA 375-95-1
Perfluorodecanoic acid PFDA 335-76-2
Perfluoroundecanoic acid PFUnA 2058-94-8
Perfluorododecanoic acid PFDoA 307-55-1
Perfluorotridecanoic acid PFTrDA 72629-94-8
Perfluorotetradecanoic acid PFTeDA 376-06-7
Perfluoroalkyl sulfonic acids
Acid Form
Perfluorobutanesulfonic acid PFBS 375-73-5
Perfluoropentansulfonic acid PFPeS 2706-91-4
Perfluorohexanesulfonic acid PFHxS 355-46-4
Perfluoroheptanesulfonic acid PFHpS 375-92-8
Perfluorooctanesulfonic acid PFOS 1763-23-1
Perfluorononanesulfonic acid PFNS 68259-12-1
Perfluorodecanesulfonic acid PFDS 335-77-3
Perfluorododecanesulfonic acid PFDoS 79780-39-5
Fluorotelomer sulfonic acids
1 H ,1 H , 2 H , 2 H -Perfluorohexane sulfonic acid 4:2FTS 757124-72-4
1 H ,1 H , 2 H , 2 H -Perfluorooctane sulfonic acid 6:2FTS 27619-97-2
1 H ,1 H , 2 H , 2 H -Perfluorodecane sulfonic acid 8:2FTS 39108-34-4
Perfluorooctane sulfonamides
Perfluorooctanesulfonamide PFOSA 754-91-6
N-methyl perfluorooctanesulfonamide NMeFOSA 31506-32-8
N-ethyl perfluorooctanesulfonamide NEtFOSA 4151-50-2
Perfluorooctane sulfonamidoacetic acids
N-methyl perfluorooctanesulfonamidoacetic acid NMeFOSAA 2355-31-9
N-ethyl perfluorooctanesulfonamidoacetic acid NEtFOSAA 2991-50-6
Perfluorooctane sulfonamide ethanols
N-methyl perfluorooctanesulfonamidoethanol NMeFOSE 24448-09-7
N-ethyl perfluorooctanesulfonamidoethanol NEtFOSE 1691-99-2
Per- and Polyfluoroether carboxylic acids
Hexafluoropropylene oxide dimer acid HFPO-DA 13252-13-6
4,8-Dioxa-3 H -perfluorononanoic acid ADONA 919005-14-4
Perfluoro-3-methoxypropanoic acid PFMPA 377-73-1
Perfluoro-4-methoxybutanoic acid PFMBA 863090-89-5
Nonafluoro-3,6-dioxaheptanoic acid NFDHA 151772-58-6
1
NPDES Permit No. MA0103284
202 3 Reissuance
Appendix H: PFAS Analyte List
Page 2 of 2
Target Analyte Name Abbreviation CAS Number
Ether sulfonic acids
9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid 9Cl-PF3ONS 756426-58-1
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid 11Cl-PF3OUdS 763051-92-9
Perfluoro(2-ethoxyethane)sulfonic acid PFEESA 113507-82-7
Fluorotelomer carboxylic acids
3-Perfluoropropyl propanoic acid 3:3FTCA 356-02-5
2 H ,2 H ,3 H ,3 H -Perfluorooctanoic acid 5:3FTCA 914637-49-3
3-Perfluoroheptyl propanoic acid 7:3FTCA 812-70-4
2
C AM002O 4O 0.69 '
-·-··--·~ -- -
,..
.... AM400O To be closed NIA '
~ •
I~ I F I I
I I I i Draft Permit NPDES No. MA0103284
202 3 Reissuance
Attachment I: Authorized Typical Year CSO Discharge Activation and Frequency
Exhibit B
to
Second Stipulation
SUMMARY OF TYPICAL YEAR CSO ACTIVATION FREQUENCY AND VOLUME
TYPICAL YEAR
LONG TERM CONTROL PLAN 2005 (*)O
OUTFALL REFERENCE ( *)
ActivationO
Frequency Volume(MG)O
ALEWIFE BR00K 1 1
CAMOOI ' 0.19 '
<
MWR003O ' .. 0.98 ' CAM004O To be closed NIA '
r--:AM401AO ' 1.61O ' AM4018O 7 2.15 ' I ..
i.50MOOIA JO 1.67 ' I
SOMOOIO NIA Closed
OM002AO Closed NIA
SOM003O NIA Closed
SOM004 ClosedO NIA
TOTAL 7.29
UPPER MYSTIC RIVER
SOM007NMWR205A (Somerville ...
Marninal) JO 3.48
SOM007 Closed NIA
I
I TOTAL 3.48
I I
MYSTIC/ CHELSEA CONFLUENCEO I
I MWR205 Somerville Mar inal 39 60.58 ( 11: )
I
BOS013 4O 0.54O 6
BOS014 6 0 0.00
BOS015 Closed NIA 6O
80S017
HE002
I 0.02O 9
t=
C 4O 0,22
,.. HEOOJ J 0.04
,... HE004 J 0.32
::: HE008 0 0.00
TOTAL 61.72
UPPER INNER HARBOR
8OS009 ' 0.59 6
I 8OS010 4 0.72O 6O
BOS019 2 0.58
=l '
I
80S012 0.72 6O
B0S050 Closed NIA
BOS052 Closed NIA
I I I
I
r BOS057 I 0.43
BOS058 7 Closed I NIA I
I B0S060 0 0.00
MWR203 {Prison PoinOO JO 335.00O I, 9O
TOTAL 338.04
LOWER INNER HARBORO
··-
I ---
BOS003O 4 I 2.87 I 6O I
I I . I
I BOS004O ' I 1.84O I 6O I
I BOSOOSO I I 0.01O I 6O I
I
I
I
I I
I
I
I
BOS006 4O 0.24 6O
BOS007O 6O LOS 6O
TOTAL 6.01
2/28/2006 1of3O
Draft Permit NPDES No. MA0103284
202 3 Reissuance
Attachment I: Authorized Typical Year CSO DischargeActivation and Frequency Exhibit B
to
Second Stipulation
SUMMARY OF TYPICAL Yl':AR CSO ACTIVATION FRl':QUENCY ANO. VOLUME
OUTFALL
ro."iSTITUTION BEACH
MWR207
TOTAL
FORT POfNT CHANNEL
BOS062 I 0.01
BOS064 0 0.00
60$1)65 I O.O<i
80$068 0 0.00
8OS070
BOS070l08C J 2 1 1 } )
UPPS 17 71.J7
BOSO?O/RCC 2 0.26
• BOSO?Z 0 0.00
BOS07J 0 0.00 4
TOTAL
RESERVED CHANNEL
BOS076 ) 0.91 7
8OS078 3 0.28 1
00S079 I 0.04 7
BOSOSO J 0.25 7
TOTAL
NORTHERN DORCHESTER BA\'
BOS08l 0/2)w>2r NIA
005082 0125 NIA
80508) 0/25 NIA
00S084 0/25vear NIA
BOS085 0 / 25 W">lt' NIA
BOS086 0/25 vear NIA
80S087 0/25vear NIA
TOTAL
SOlITHER."i DORCHESTER BAY
u S088 Tobe dosed NIA
BOS089 lFo,; Point\ 1'o be closed NIA
BOS090 (Commeteial Point}
TOTAL
UPPER CHARLES
iBOSlll2 Closed NIA
BOS0J) Closed NIA
r'AM005 ) 0.84 8
AM007 I 0.03 8
,AM009 2 0.01 8
AM0ll 0 0.00 8
TOTAL
TYPICAL VEAk
LONG TERM CONTROL f'LAN 2005 (*)
11,Ct,vat1oa
Frequency
CEo~
To be closed
Vi>lume(MG)
NIA
0.00
73.89
1.48
0.00
NIA
0.00
0.88
REFERENCE(*)
212812006 2of 3
Draft Permit NPDES No. MA0103284
202 3 Reissuance
Attachment I: Authorized Typical Year CSO DischargeActivation and Frequency Exhibit B
to
Second Stipulation
SUMMARY OF TYPICAL YEAR CSO ACTIVATION FREQUENCY AND VOLUME
TYPICAL YEAR
LONG TERM CONTROL PLAN 2005 (*) (')
REFERENCE OUTFALL
Atnva......,
Frequw,cy \!olum"(MG)
LOWER CHARLES
BOS028 Ck>ood NIA
05042 Closed NIA
"US049 Tobe dosed NIA
.AM0l7 I 0.45 8
VIWROIO 0 0.00 2
MWR018 0 0.00 I
MWR0l9 0 0.00
vrWR020 0 0.00 '
MWR021 Closed NIA ' 1.tWR022 Ck,,..J NIA
MWIUOI fCottae.e Fanu) 2 6.30 8
'"WR023 2 IU3
SOMOIO Ck,sed NIA
TOTAL 6.88
NEPONSET RIVER
""S09J Closed NIA
805095 Ck,,..J NIA
TOTAi, 0.00
0ACK BAY FENS
805046 2 5.38
TOTAL 5.38
(*} long-lem1 Control Plan activation frequency and volumes were estahll!ltl.ed In tlte 1997 CSO f.tcilities PLm and Etiviromental Impact Report
or as noted in the "Reference~ column.
I· Re-assessing Long Tc:m1 Fioatables C®tt:ol for OutfaUs MWROl 8, 019 and 020, February 200 L
2· Repotton RewAssessmcnt ofCSO Activation Frequency and Volume forOu1faU MWROIO. April 2001, and supplemental
kttcrrepon {Mttcalf& Eddy, Inc.), May 31. 2001.
3- Report on Re-Assessment ofCSO Activation Frequency and Volume to Ootchester Brook Conduit and Oulfall 80S086, January 2001
and supplemental letter report (Metcalf & 13ddy, {nc,), June 28, lOO L
4- MWRA untg Tenn CSO Control Pl:i.n, Fort Point Channel Sewer Separation and System Optimization (>roject, Level ofCootrol at
CSO Outfalls 8OS072 and BOS013, hme 7, 2004.
5- Final Variance Report for Alewife Brook and the Upper Mystic River. Jul}' 2003. and supplement.al letter report (Metcalf &Eddy, Inc.), July B, 2(IOJ_
6- East Boston Bran<:h Sewer Relier Project Reevaluation Report, February 2004.
7- Supplemental Facilities Plan and Environmental lrnpact Report oo the Long-term CSO Cootrol Plan for North Dorchcsler Bay
arnf Reserved OtanneL April 27. 2-004.
8- Recommendations and Proposed Schedule for Long-TermCSO Control for tlw Charles River, Alewife Brook and East Boston, August 2, 2005;
MWRA Revised Recontruooded CSO Control Man for Ute Charles River, Typical Year CSO Dtseharge Activations and Volumes,
November 15, 2005; MWRA Loog-Tenn CSO Control Plan. Response to Addi(ional EPA Questions Reagarding Prison Point Discharges,
January 9, 2005 (2006).
9, MWRA Long Term CSO Cootrol Plan Target CSO Activation Frequertey and Volume by Outfall, December 9. 2005.
212812006 3of3
Commonwealth of Massachusetts
Executive Office of Energy & Environmental Affairs
Department of Environmental Protection
Northeast Regional Office• 2058 Lowell Str eet , Wilmington MA 01887 • 978-694-3200
Charles D. Baker
Governor
Karyn E. Polito
Lieutenant Governor
Kathleen A. Theoharides
Secretary
Martin Suube rg
Commissioner
FINAL DETERMINATION TO ADOPT A VARIANCE
FOR COMBINED SEWER OVERFLOW DISCHARGES
TO
CHARLES RIVER BASIN
The Massachusetts Department of Environmental Protection ("MassDEP") hereby adopts a
Variance for Combined Sewer Overflow ("CSO") Discharges to the Charles River Basin (the
"Variance"), originally issued on October 1, 1998, from September 1, 2019 to August 31, 2024.
This discharger-specific variance, if finalized, would authorize limited CSO discharges from the
Massachusetts Water Resources Authority ("MWRA") and the City of Cambridge which are
subject to NPDES permit Nos. MAO 103284 and MA0l 01974, respectively. During wet weather
. events where the limited CSO discharges are authorized, Class B requirements at 314 CMR
4.05(3)(b) for bacteria, solids, color and turbidity, and taste and odor may not be met. The
Variance is a water quality standards revision subject to EPA review and approval under EPA' s
regulations at 40 CFR Part 131. It is adopted pursuant to the Massachusetts Surface Water
Quality Standards ("SWQS") at 314 CMR 4.00 and the federal Water Quality Standards
regulations at 40 CFR Part 131, and subject to the specific conditions which follow. This
Variance is intended to establish requirements to (1) achieve the highest attainable water quality
conditions in the receiving water; (2) provide for an assessment of the level of CSO control
achieved, and the associated water quality impacts of CSO and non-CSO sources; (3) establish
requirements for public notification of CSO events and their impacts; and (4) continue to assess
the costs and feasibility of achieving higher levels of CSO control beyond the requirements of
this variance. MWRA currently remains subject to the orders of the United States District Court
for the District of Massachusetts, Civil Action Nos. 85-0489-MA and 83-1614-MA, including
amended Schedule Seven, dated October 19, 2011 (the "Federal Court Order") regarding its
implementation of the revised Long-Term CSO Control Plan ("LTCP").
MassDEP adopts this Variance based on its determination described in the accompanying fact
sheet that implementation of more stringent CSO controls to meet the underlying designated use
and criteria at this time would result in substantial and widespread social and economic impact as
specified in 314 CMR 4.03(4)(f) and 40 CFR 13 l .10(g)(6). Further, implementation of the
requirements that follow represent the highest attainable interim effluent conditions during the
term of the variance until such time as information to support further regulatory determinations is
available. Information gathered during the term of the CSO Variance is intended to be used to
make a subsequent determination on the appropriate water quality standard for the Charles River
segments that are currently affected by CSO discharges. Issuance of this Variance for CSO
discharges to the Charles River Basin is consistent with EPA's regulations at 40 CFR 131.14 and
with the U.S. Environmental Protection Agency's Guidance (Coordinating CSO Long-Term
Planning with Water Quality Standard Reviews, July 31, 2001), which states that longer term
variances and renewal of variances are warranted given the extended duration necessary for
implementation oflong-term control plans.
MWRA and the City of Cambridge, as of December 2015, have completed all construction work
in MWRA's LTCP, consistent with the requirements of the Federal Court Order. MWRA is now
in the midst of a CSO Performance Assessment, also a requirement of the Federal Court Order,
which is intended to document the level of CSO control achieved. This Variance affirms that, as
an element of this Assessment work, MWRA undertake a CSO/water quality assessment,
through development and use of a receiving water model, to determine the impacts of CSO and
non-CSO sources in the Charles River, pursuant to EPA's 1994 Combined Sewer Overflow
(CSO) Control Policy ("EPA CSO Policy").
Once approved by EPA under CWA section 303(c), this Variance and its conditions will be
incorporated into NPDES permits for the MWRA and the City of Cambridge at the time of
reissuance of those permits, consistent with 40 CFR 131.14(c). Failure by the MWRA and/or the
City of Cambridge to comply with the conditions of this Variance following its effective date
and as implemented in their NPDES permits will constitute a violation of the permit, as well as
the Massachusetts SWQS (314 CMR 4.00) and the Surface Water Discharge Permit Program
regulations (314 CMR 3.00).
The Variance is a short-term modification of the Massachusetts SWQS, issued by MassDEP and
subject to EPA approval. The Variance allows limited CSO discharges from the outfalls along
the Charles River Basin permitted to MWRA and the City of Cambridge, subject to specific
conditions. Other standards and criteria of the receiving water's Class B designation are
unaffected and remain in force.
VARIANCE CONDITIONS
The Variance is conditioned upon MWRA and the City of Cambridge complying with their
individual and joint requirements, as identified below:
A. Level of Required CSO Control During Variance
Per the requirements included in the "Second Stipulation of the United States and the
Massachusetts Water Resources Authority on Responsibility and Legal Liability for
Combined Sewer Overflow Control" ("Second Stipulation"), filed March 15, 2006, as
amended in the aforementioned actions, CSO discharges shall be limited to those set forth in
attached Exhibit B, with allowance for any conditions that exceed Typical Year 1 conditions.
1 "Typical Year" rainfall has been the basis for development, recommendation and approval of MWRA's LTCP, the establishment of the federal
court mandated levels of control, and the assessment of system performance toward attainment of the LTCP levels of control. The Typical Year
,vas developed from 40 years of rainfall records (1949-1987, plus 1992), and it includes 93 stom1s with a total precipitation of 46.8 inches.
2
Consistent with 40 CFR 131. 14(b)(l )(ii)(AJ(3), this is the effluent condition that reflects the
greatest pollutant reduction achievable within the five-year term of this variance with the
pollutant control technologies installed at the time the state is adopting this variance.
B. Receiving Water Quality Monitoring
MWRA shall continue and expand the water quality monitoring program in the Charles River
to demonstrate the effectiveness of CSO controls implemented in the watershed. The work
shall be adequate to assess the water quality impacts of remaining CSO pollutant sources and
loads over a range of storm events, and the associated level of attainment of water quality
standards in the Charles River.
On or before July 15 each year, for the duration of this Variance, MWRA shall submit to
MassDEP and EPA a report on the previous year's sampling program. The report shall
include a summary of the receiving water sampling data collected over the past calendar
year, including sampling locations and parameters, and comparisons between results during
wet and dry weather. a characterization of rainfall events for which wet weather sampling
was done, and an assessment of the water quality impacts ofCSO and non-CSO sources.
C. CSO Performance Assessment
I. CSO Activations and Volumes
By December 31, 2021, MWRA shall submit the results of the CSO Performance
Assessment to EPA and MassDEP, documenting the level of CSO control achieved through
implementation of the LTCP throughout the CSO planning area, in regard to CSO activations
and volumes in the Typical Year, relative to the Second Stipulation levels of control (Exhibit
B), and shall also post the Assessment Report on its website. During the course of
completing this work, MWRA shall also undertake the following actions:
a) Progress Reports: MWRA shall submit progress reports to MassDEP and to EPA,
and shall post the reports to the MWRA website in accordance with the following
schedule:
1. Progress Reports #1. 2, and 3 shall be submitted and posted on or before
October 31, 2019, and together shall be inclusive of all work done for the
CSO Performance Assessment through June 30. 2019;
11. Progress Report #4 shall be submitted and posted on or before April 30. 2020.
and shall be inclusive of all work done for the CSO Performance Assessment
through December 31, 2019:
111. Progress Report #5 shall be submitted and posted on or before October 31,
2020. and shall be inclusive of all work done for the CSO Performance
Assessment through June 30. 2020;
1v. Progress Report #6 shall be submitted and posted on or before April 30, 202 I.
and shall be inclusive of all work done for the CSO Performance Assessment
through December 31, 2020; and
3
v. Progress Report #7 shall be submitted and posted on or before October 31,
2021. and shall be inclusive of all work done for the CSO Performance
Assessment through June 30, 2021.
Progress Reports shall include a summary of work completed. metering data
collected, integration with MWRA's sewer system model, estimated CSO discharges
from metering data (or model simulations when approved by MassDEP), a discussion
of any locations where metered, or when approved by MassDEP, modeled CSO
discharges appear to exceed Second Stipulation levels of CSO control, and any
measures taken to optimize the Nine Minimum Control actions to further control CSO
discharges.
b) Public Meetings:
1. MWRA shall arrange for public meetings in May 2020 and May 2021, to
present information on the progress of the work and findings to date, and
allow for public input;
11. MWRA shall arrange for a public meeting in February 2022 to present the
findings of the CSO Performance Assessment, and to allow public comment
on the Assessment and its findings; and
111. Notice for the date, time, and location of each public meeting shall be
provided in the Environmental Monitor at least thirty days in advance of each
public meeting.
2. Assessment of CSO Water Quality Impacts
MWRA shall implement the Receiving Water Model Workplan, dated May 24, 2019 and
revised July 18, 2019, along with the Receiving Water Modeling of Upper Mystic
River/Alewife Brook and Charles River Basin: Work Plan for Stormwater and Combined
Sewer Overflow Monitoring, 2019-2020, dated June 6, 2019 and revised August 27, 2019,
and develop and calibrate a receiving water quality model, and use such model to present
information on the water quality impacts of CSO and non-CSO discharges in the Charles
River Basin watershed.
The Final CSO Water Quality Impact Report shall be submitted to MassDEP and EPA on or
before December 31, 2021, and shall include a description of the data collected and used for
developing and calibrating the model; information on CSO and non-CSO water quality
impacts for a range of design storms and the Typical Year; and a sensitivity analysis showing
the water quality benefits of further pollutant reductions in upstream sources, storm water,
and CSO discharges.
D. Notification to the Public of CSO Discharges and Impacts
I. MWRA and the City of Cambridge shall maintain outfall signs that are visible both from
the shore and from in stream locations for their permitted CSO discharges. Pursuant to
their NPDES Permits. the following language, at a minimum. shall be included:
4
WARNING:
WET WEATHER
SEWAGE DISCHARGE
OUTFALL (discharge serial number)
2. MWRA and the City of Cambridge shall issue a joint press release by April 15 of each
year to watershed advocacy groups, local health agents, and newspapers of local
circulation in the Charles River watershed, which shall include general information on
CS Os, the location of outfalls in the Charles River watershed, and potential health risks
posed by exposure to CSO events.
3. MWRA and the City of Cambridge shall, by December 31, 2020, develop and implement
a CSO Subscriber-Based Notification System to provide CSO Alert Notifications to any
interested parties. MWRA and the City of Cambridge may choose to develop the
Notification System collaboratively. The Notification System shall include the following
components:
a. A CSO Alert Notification shall be issued no later than 4 hours after becoming
aware ofa CSO event from one or more of the permittee's CSO outfalls, but in no
event later than 12 hours after onset of the CSO discharge, which shall be issued
to: MassDEP, EPA, Cambridge Public Health Department, City of Boston Public
Health Commission, Boston Water and Sewer Commission, the Charles River
Watershed Association, and any person subscribed to receive such Alert
Notifications.
The CSO Alert Notification shall provide, at a minimum, the following
information:
1. Outfall location(s);
11. Approximate time and date of onset of the discharge;
111. Whether, at the time of notification, the discharge has ceased, and if so,
the approximate time that the discharge ended;
1v. Waters and land areas potentially affected by such discharge:
v. Precautionary measures for the public to avoid health risks from contact
with et11uent; and
v1. Link to the permittee's website for additional information on CSOs and its
CSO abatement program.
Until such time as the Subscriber-based system is in place, the MWRA shall
continue its current practice of providing a CSO Alert email notification to
MassDEP, EPA, the Community Sailing Program, health departments, and
boathouses in the areas affected by CSO discharges, within 12 hours of a CSO
discharge event at the MWRA Cottage Farm CSO Treatment Facility.
b. MWRA, and the City of Cambridge shall each establish and maintain a public
website, which shall include, at a minimum, the information listed below, for their
5
permitted CSO outfalls in the Charles River Basin. If agreed upon by MWRA
and the City of Cambridge, this requirement may be met by one entity compiling
and posting the data on their website, and the second entity providing a link on
their own website to the data.
1. A map showing the locations of the CSO outfalls, correlating to the CSO
outfall numbers included in their respective NPDES Permits;
11. On or before December 31, 2020. instructions on how an interested person
can self-register for the CSO Subscriber-Based Notification System;
111. Within 5 business days of any CSO Alert Notification issued, updated
information on the estimated duration and volume of the CSO discharge
and event rainfall data; and
1v. Annual lists of the permittees· CSO outfalls within the variance waters
with information compiled on duration and volume of discharges from
each outfall, as well as cumulative discharge volume from all CSOs. Each
annual calendar year summary shall be updated and posted on the website
no later than April 30 th of each year.
E. Other Actions to Minimize CSO Discharges
I. MWRA and the City of Cambridge shall continue to implement the Nine Minimum
Controls (NMC), as set forth in their respective NPDES Permits and the Variance
conditions. which must include the following components:
a. Proper operation and regular maintenance programs for the sewer system and
the CSOs.
b. Maximum use of the collection system for storage.
c. Review and modification of the pretreatment program to assure CSO impacts
are minimized.
d. Maximization of flow to the POTW for treatment.
e. Prohibition of dry weather overflows from CSOs.
[ Control of solid and floatable materials in CSOs.
g. Pollution prevention programs that focus on contaminant reduction activities.
h. Public notification to ensure that the public receives adequate notification of
CSO occurrences and CSO impacts.
1. Monitoring to effectively characterize CSO and the efficacy of CSO controls.
Any enhancements to the MWRA and community NMC programs identified by
MassDEP or the permittees during the CSO Performance Assessment can and shall be
implemented after obtaining all necessary approvals, providing the enhancements do not
conflict with the overall goals and requirements of the LTCP, as measures to further
reduce CSO discharges so that highest attainable interim effluent conditions can be
achieved and maintained during the Variance period.
2. Variance Pollutant Minimization Program as required by 40 CFR 13 l. l 4(b)( I )(ii)(A)(3 ):
6
MWRA with assistance/support from the City of Cambridge. shall implement the
Additional System Optimization measures as set forth in the scope and schedule of
actions in attached Exhibit A. MWRA shall coordinate with the City of Cambridge to
evaluate the impact of any Additional System Optimization measures on both systems·
performance. Beginning in 2021 and on or before January 31 of each year until the end of
this Variance, MWRA shall submit to MassDEP and EPA and shall post on its website,
progress reports on the implementation of the Additional System Optimization measures.
Exhibit A represents the pollutant minimization activities that MWRA will implement in
this variance term.
3. MWRA shall continue to provide technical assistance related to the identification and
removal of Infiltration/Inflow (Ill) to member communities. Where requested by any
member community, or by MassDEP or EPA, MWRA shall provide information from
MWRA metering data, including but not limited to:
a. A system map showing locations of MWRA metering points;
b. MWRA metering data by each MWRA member sewer community, broken
down into estimates of average monthly sanitary flow, average monthly
infiltration and average monthly inflow; and
c. MWRA metering data by meter subarea correlating to a specific storm event.
4. The City of Cambridge shall consider use of Green Infrastructure technologies where
feasible to increase storrnwater infiltration.
F. Updated CSO Control Planning
On or before April L 2022. MWRA and the City of Cambridge shall each submit for
MassDEP and EPA review and approval, a scope and schedule for an updated CSO Control
Plan for the CSO outfalls that each perrnittee owns and operates that discharge to the Charles
River Basin. The updated CSO Control Plan shall conform to the EPA CSO Policy and
MassDEP's 1997 Guidancejhr Abatement of Pollution from CSO Discharges, and shall
specifically include the following elements:
I. A description of the existing level of CSO control;
2. An evaluation of the costs and performance (i.e .. effectiveness in reducing CSO
discharge frequency and/or volume) and water quality improvements achieved by
additional CSO control alternatives, up to and including. elimination of CSO discharges.
For the City of Cambridge. use of Green Infrastructure technologies shall be considered.
The evaluation of costs and water quality benefits may include the impacts of storrnwater
discharges;
3. A public participation plan sufficient to provide for ample opportunities for the public to
be informed about the development of the Plans at critical junctures. and to have
opportunities to provide informed comments on the CSO abatement alternatives and
recommendations. The scope of the plan. as an element of full scope of work, shall be
subject to MassDEP review and approval. This plan shall include submittals to comply
with the Massachusetts Environmental Policy Act 301 CMR 11.00:
7
4. An affordability analysis consistent with EPA ·s November 24. 2014 ,'vlemorandum an
Financial Capability Assessment Frameworkfo r Municipal Clean Wat er rlct
Requirements, along with any other relevant information to assess financial capacity;
5. A Draft Recommended Plan, to be submitted to MassDEP and EPA by June 30. 2023,
which achi eves compliance with the federal Clean Water Act, the federal Water Quality
Standards regulations (40 CFR Part 13 I) and the Massachusetts Surface Water Qua Iity
Standards regulations (3 14 CM R 4.00), supporting as needed any recommendations for
changing the classification of any CSO-impacted receiving waters and Use Attainability
Analyses.
6. A Final Recommended Plan, to be submitted to MassDEP and EPA for review and
approval by December 3 1, 2023 , which responds to comments received on the Draft
Recommended Plan.
Subject to the conditions included in this Variance, MWRA and the City of Cambridge shall be
authorized to discharge limited CSOs during wet weather events to the Charles River Basin.
Date Issued
--1(~'-(Yl ~
Kathleen M. Baskin
Assistant Commissioner
Bureau of Water Resources
'f? -- 3 ( - J..b l <"j
Effective Date
8
Exhibit A
MWRA CSO Variance
Additional System Optimization Measures
Below is a summary of the specific additional system optimization measures that MWRA will
undertake during a 5-year variance period beginning September I, 2019. These activities are
intended to further MWRA ·s goals of improving water quality in the Lower Charles River.
Upper Mystic River, and Alewife Brook. These measures are consistent with the requirements of
40 CFR 131.14. and allow for progress to be made towards attaining designated use(s) and water
quality criteria. Collectively with the other elements of the CSO Variance requirements. these
efforts comprise the Pollutant Minimization Program to be implemented during the course of the
CSO Variance. Additional CSO system optimization efforts and on-going implementation of the
"CSO Nine Minimum Controls" will be informed by MWRA's hydraulic model, which is in the
process of being calibrated with extensive flow and overflow meter data being gathered, which
commenced in 2018. MWRA expects the calibration to be complete by the fall of 2019. These
efforts will also be informed by MWRA 's updated receiving water quality models, which will be
produced and available in the early years of the variance period.
Mystic River Watershed Project
I. Evaluate alternatives to reduce CSO activation frequency and volume at the Somerville
Marginal CSO Treatment Facility. and associated CSO outfalls SOM007A/MWR205A, and
MWR205. while avoiding any increase in the frequency and volume of CSO discharges at
MWRA's Prison Point CSO Treatment Facility (MWR203). and CSO outfalls CAM0l 7 and
BOSO 17. Alternatives to be evaluated, at a minimum. will include:
• Construction of dry weather connection relief/control from the City of Somerville's
CSO regulator RE071A to MWRA's Somerville-Medford Branch Sewer; and
• Relocation of MassDOT 1-93 drainage from upstream to downstream of the
Somerville-Marginal facility to reduce the frequency and volume of facility
activations.
The work will need to address heavy traffic and underground utilities in the project area, and
will also require close coordination with MassDOT. MWRA will develop a Somerville
Marginal CSO Reduction Plan, which will include the outcome of the feasibility study:
preliminary design plans for projects recommended to further reduce CSO discharges at this
facility, and a schedule for final design and construction of recommended facilities.
Construction will proceed unless the feasibility evaluation clearly demonstrates that
construction is technically infeasible. that the project will not provide water quality benefits
through the reduction of CSO volume or frequency. or that the costs. alone or in conjunction
with other activities specified in Exhibit A. would cause widespread social and economic
impact.
MWR205 & SOM007/MWR205A Somerville Marginal CSO Reduction Project, Study
and Preliminary Design
9
Notice to Proceed - December 2020
Study Report/Preliminary Design Submittal to MassDEP for review and approval -
December 2021
Alewife Brook Project
2. MWRA proposes to evaluate maximizing beneficial use of enhanced pumping capacity at the
recently rehabilitated Alewife Brook Pump station to lower wastewater elevations in the
upstream collection system and potentially reduce CSO activations and volumes at upstream
CSO outfalls CAM00l, CAM002. MWR003, and SOM00IA. During the Variance period,
MWRA will assess alternative pumping strategies and expected upstream benefits using the
MWRA's calibrated hydraulic model. Alternatives determined to provide potential benefits
will be tested for a range of storm events. MWRA will develop an Alewife Brook Pump
Station Optimization Report with findings and recommendations, including modeled control
alternatives and testing, and an implementation plan to establish a schedule for any required
programming of automated facility control changes and operator training, which shall
become the standard operating procedure to minimize CSO discharges. Implementation will
proceed unless the feasibility evaluation clearly demonstrates that construction is technically
infeasible, that the project will not provide water quality benefits through the reduction of
CSO volume or frequency, or that the costs, alone or in conjunction with other activities
specified in Exhibit A, would cause widespread social and economic impact.
Alewife Brook Pump Station Optimization Evaluation Project
Notice to Proceed - April 2020
Alewife Brook Pump Station Optimization Report submittal to MassDEP for review and
approval - April 2021
Alewife Brook and Charles River Watershed
3. Using the calibrated hydraulic model and coordinating technical evaluations with the Cities
of Cambridge and Somerville and the Boston Water and Sewer Commission. MWRA will
conduct system optimization evaluations at the remaining active regulators tributary to CSO
outfalls discharging to the Alewife Brook and Charles River watersheds. The MWRA will
then implement recommended modifications to those regulators owned by MWRA and will
provide technical support to member communities in their efforts to implement
recommended modifications to community owned CSO regulators. The MWRA anticipates
evaluating and implementing optimization measures such as regulator closing, overflow weir
modification or raising, dry weather connection relief and flow reallocation opportunities.
System optimization on a regulator by regulator basis is an important component of the Nine
Minimum Control measures. The improved hydraulic model now being calibrated with
extensive metering data will facilitate MWRA 's ability to further refine the components of
individual regulators. These refinements are expected to help reduce frequency and volume
of CSO discharges while also protecting against adverse impacts. such as upstream system
IO
flooding, especially in larger storms. or higher CSO discharges at other hydraulically related
outfalls. A preliminary list of tasks is provided below to support the 2-year study and
preliminary design schedule:
• Meeting and coordinating with CSO communities to determine what
modifications/studies they have already performed. areas of concern for
flooding (historic record research). planned community improvements in
upstream systems. recommendations communities may have to modify regulator
structures/shift flows, etc.
• Extending MWRA's hydraulic model into upstream pipe networks if needed to
better assess proposed modification impacts on systems tributary to each
regulator.
• Studying the hydraulics of the existing system for various storm events to look
for opportunities to maximize flows to the wastewater conveyance system
throughout various types of storm events (high intensity short duration. long
duration low intensity, etc.), while maintaining protective relief in larger storms.
• Developing proposed modifications to regulators (weir height adjustment).
additional relief opportunities during large events (e.g .. bending weirs). dry
weather connection modifications (increase size, one-way valve control. etc.) to
take advantage of any available hydraulic capacity in the downstream
interceptors.
• Performing model simulations of typical storm events as well as large events
(IO - 25 year recurrence interval) to evaluate proposed modification benefits
and potential adverse impacts.
• Developing and garnering consensus on sewer operation modifications.
• Developing preliminary design of recommended/approved sewer operation
modifications for those which require excavation/significant construction for
modification to the regulators.
Implementation will proceed unless the feasibility evaluation clearly demonstrates that
construction is technically infeasible. that the project will not provide water quality benefits
through the reduction of CSO volume or frequency, or that the costs. alone or in conjunction
with other activities specified in Exhibit A. would cause widespread social and economic
impact.
CSO System Optimization for Alewife Brook and Lower Charles River Basins Project,
Study and Preliminary Design
Notice to Proceed - December 2020
System Optimization Report submittal to MassDEP for review and approval - December
2022
I I
EXH IBIT B
LTCP Levels of Contro l from Second Stipulation
LONG TERl\I CONTROL PLAt. ~
CSOOUTFALL TYPICAL YEAR
Activation Frequency Volume (l\IG)
.-\LD\lFE BROOK
CAM00I 5 0.19
CAM002 4 0.69
M\VR003 5 0.98
CAM004 To be closed NIA
CAM:400 To be closed N.'A
CAM401A 5 1.61
CAM401B 7 1. 15
S01v!OOIA 3 1.67
s o :MOOI Closed NIA
SOM002A Closed N/A
SOM003 Closed NIA
s o :M004 Closed NIA
TOT.-\L 7.29
n>PER ~ffSTIC RIYER
SOM007A.'MWR205A (Somerville Marwial) 3 3.48
SOM007 Closed NIA
TOT.-\L 3A8
:m:STIC / CHELSL\ co.xn.n :xn:
M\VR205 (Somerville l\'iai~ l) 39 60.58
BOS0 13 4 0.54
BOS0 U 0 0.00
BOS015 Closed NIA
BOS017 I 0.02
CHE002 4 0.22
CHE003 3 0.04
C 1IE004 3 0.32
CHE008 0 0.00
TOT.-\L 61.71
n>PER L\ :-""ER H.-\RBOR
BOS009 5 0.59
BOS0 I0 4 0.71
BOS012 5 0.71
BOS019 1 0.58
BOS050 Closed N/A
BOS052 Closed NIA
BOS057 I O A3
BOS05S Closed NIA
BOS060 0 0.00
~!\VR203 (Prison Point) 17 243.00
TOT.-\L ~46.04
12
LONG TERM CONTROL PL..\i~
CSOOUTFALL TYPICAL \ 'EAR
Activation Frequency Volume (MG)
LOW"ER D,").""E:R H..-\RBO R
BOS003 4 2.87
BOS004 5 1.84
BOS005 I 0.01
BOS006 -t 0.24
BOS007 6 1.05
TOT.\L 6.01
C O:,\"STITl'"IlO:,\" BEACH
M'\\IR.207 Closed NIA
TOT.\L 0.00
FORT POD-1 CHA. '\")."IL
BOS062 I 0.01
BOS064 0 0 .00
BOS065 I 0.06
BOS068 0 0.00
BOS070
BOS0701 DBC 3 2. 19
UPPS 17 7 1.37
BOS070/RCC 2 0.26
BOS072 0 0.00
BOS073 0 0.00
TOT.\L 73.89
RESER\"ID CH.-\..'\ "). "IL
BOS076 3 0.91
BOS078 3 0.18
BOS079 I 0.04
BOS080 3 0.25
TOT.\L 1.48
:.\"ORTH"ER'i DORCHESTIR B.\ Y
BOS081 0 , 25 year NlA
BOS082 0 I 25 year N1A
BOS083 0 / '15 vear NIA
BOS084 0 115 year NlA
BOS085 0 1 25 year NIA
BOS086 0 ; 25 year N/A
BOS087 0 25 year N:'A
TOT.\L 0.00
SOl"THER' i DORCHESTIR B.ff
BOS088 To be clo,;ed NIA
BOS089 (Fox Point) To be closed NlA
BOS090 (COllllllercial Point) To be clo,;ed N/A
TOT.\L 0.00
13
■
LONG TERJ. "\I CONTROL PLAN
CSOOUTFALL TI'PICAL YEAR
Actirntion Frequency Volume (l\IG)
ll'PER CH.-\RLES
BOS032
BOS033
CAM005
CAfvi007
CAfvi009
C'Af..[011
TOT..\L
Closed
Closed
3
I
1
0
NIA
NIA
o.s.i
0.03
0.01
0.00
0.88
LOWER CH...\.RLES
BOS028
BOS042
BOS049
CAfvf017
~fWROI0
~f\VROIS
MWR.019
MW'R.020
~IWR021
:MWR.022
MWR.201 (Cottage Faim)
~f\VR.023
SOMOl0
TOT..\L
Closed
Closed
To be closed
I
0
0
0
0
Closed
Closed
2
)
Clo<;ed
N/A
NIA
NIA
0.45
0.00
0.00
0.00
0.00
NIA
NIA
6.30
0.13
NIA
6.SS
'.\"IPO);SET Rn"IR
BOS093
BOS095
TOT..\L
Closed
Clo.sed
N/A
NIA
0.00
B.KK B.-\Y ITXS
BOS046
TOT..\L
2 5.38
~.38
14
Commonwealth of Massachusetts
Executive Office of Energy & Environmental Affairs
Department of Environmental Protection
Northeast Regional Office• 2058 Lowell Street, Wilmington MA 01887 • 978-694-3200
Charles D. Baker
Governor
Karyn E. Polito
Lieutenant Governor
Kathleen A. Theoharides
Secretary
Martin Suuberg
Commissioner
FINAL DETERMINATION TO ADOPT AVARIANCE
FOR COMBINED SEWER OVERFLOW DISCHARGES
TO
ALEWIFE BROOK/UPPER MYSTIC RIVER BASIN
The Massachusetts Department of Environmental Protection ("MassDEP") hereby adopts a
Variance for Combined Sewer Overflow ("CSO") Discharges to the Alewife Brook/Upper
Mystic River Basin (the "Variance"), originally issued on March 5, 1999, from September 1,
2019 to August 31, 2024. This discharger-specific variance, if finalized, would authorize limited
CSO discharges from the Massachusetts Water Resources Authority ("MWRA") and the Cities
ofCambridge and Somerville, which are subject to NPDES permit Nos. MA0103284,
MA0101974, and MA0101982, respectively. During wet weather events where the li_ mited CSO
discharges are authorized, Class B requirements at 314 CMR 4.05(3)(b) for bacteria, solids, color
and turbidity, and taste and odor may not be met. The Variance is a water quality standards
revision subject to EPA review and approval under EPA's regulations at 40 CFR Part 131. It is
adopted pursuant to the Massachusetts Surface Water Quality Standards ("SWQS") at 314 CMR
4.00 and the federal Water Quality Standards regulations at 40 CFR Part 131, and subject to the
specific conditions which follow. This Variance is intended to establish requirements to (1)
achieve the highest attainable water quality conditions in the receiving water; (2) provide for an
assessment of the level of CSO control achieved, and the associated water quality impacts of
CSO and non-CSO sources; (3) establish requirements for public notification of CSO events and
their impacts; and (4) continue to assess the costs and feasibility of achieving higher levels of
CSO control beyond the requirements of this variance. MWRA currently remains subject to the
orders of the United States District Court for the District of Massachusetts, Civil Action Nos. 85 -
0489-MA and 83-1614-MA, including amended Schedule Seven, dated October 19, 2011 (the
"Federal Comt Order") regarding its implementation of the revised Long-Term CSO Control
Plan ("LTCP").
MassDEP adopts this Variance based on its determination described in the accompanying fact
sheet that implementation of more stringent CSO controls to meet the underlying designated use
and criteria at this time would result in substantial and widespread social and economic impact as
specified in 314 CMR 4.03(4)(f) and 40 CFR 131.10(g)(6). Further, implementation of the
requirements that follow represent the highest attainable interim effluent conditions during the
This information Is available in alternate format. Contact Michelle Waters-Ekanem, Director of Diversity/Civil Rights at 617-292-5751.
TTY# MassRelay Service 1-800-439-2370
MassDEP Website: www.mass.gov/dep
Printed on Recycled Paper
term of the variance, until such time as information to support further regulatory determinations
is available. Information gathered during the term of the CSO Variance is intended to be used to
make a subsequent determination on the appropriate water quality standard for the Alewife
Brook and the Upper Mystic River segments that are currently affected by CSO discharges.
Issuance of this Variance for CSO discharges to the Alewife Brook/Upper Mystic River is
consistent with EPA's regulations at 40 CFR 131.14, and with the U.S. Environmental Protection
Agency's Guidance (Coordinating CSO Long-Term Planning with Water Quality Standard
Reviews, July 31, 2001), which states that longer term variances and renewal of variances are
warranted given the extended duration necessary for implementation of long-term control plans.
MWRA and the Cities of Cambridge and Somerville, as of December 2015, have completed all
construction work in MWRA's LTCP, consistent with the requirements of the Federal Court
Order. MWRA is now in the midst of a CSO Performance Assessment, also a requirement of the
Federal Court Order, which is intended to document the level of CSO control achieved. This
Variance affirms that, as an element of this Assessment work, MWRA undertake a CSO/water
quality assessment, through development and use of a receiving water model, to determine the
impacts of CSO and non-CSO sources in Alewife Brook and the Upper Mystic River, pursuant to
EPA's 1994 Combined Sewer Overflow (CSO) Control Policy ("EPA CSO Policy").
Once approved by EPA under CWA section 303(c), this Variance and its conditions will be
incorporated into NPDES permits for the MWRA and the Cities of Cambridge and Somerville at
the time of reissuance of those permits, consistent with 40 CFR 131.14(c). Failure by the
MWRA and/or the Cities of Cambridge or Somerville to comply with the conditions of this
Variance following its effective date and as implemented in their NPDES permits will constitute
a violation of the permit, as well as the Massachusetts SWQS (314 CMR 4.00) and the Surface
Water Discharge Permit Program regulations (314 CMR 3.00).
The Variance is a short-term modification of the Massachusetts SWQS, issued by MassDEP and
subject to EPA approval. The Variance allows limited CSO discharges from the outfalls along
the Alewife Brook/Upper Mystic River permitted to MWRA and the Cities of Cambridge and
Somerville, subject to specific conditions. Other standards and criteria of the receiving waters'
Class B designation are unaffected and remain in force.
VARIANCE CONDITIONS
This Variance is conditioned upon MWRA and the Cities of Cambridge and Somerville
complying with their individual and joint requirements, as identified below:
A. Level of Required CSO Control During Variance
Per the requirements included in the "Second Stipulation of the United States and the
Massachusetts Water Resources Authority on Responsibility and Legal Liability for
Combined Sewer Overflow Control" ("Second Stipulation"), filed March 15, 2006, as
amended in the aforementioned actions, CSO discharges shall be limited to those set forth in
2
attached Exhibit B, with allowance for any conditions that exceed Typical Year 1 conditions.
Consistent with 40 CFR l 3 l. l 4(b )( I )(ii)(A)(3 ). this is the effluent condition that reflects the
greatest pollutant reduction achievable within the five-year term of this variance with the
pollutant control technologies installed at the time the state is adopting this variance.
B. Receiving Water Quality Monitoring
MWRA shall continue and expand the water quality monitoring program in the Alewife
Brook/Upper Mystic River to demonstrate the effectiveness of CSO controls implemented in
the watershed. The work shall be adequate to assess the water quality impacts of remaining
CSO pollutant sources and loads over a range of storm events, and the associated level of
attainment of water quality standards in Alewife Brook and the Upper Mystic River.
On or before July 15 each year, for the duration of this Variance, MWRA shall submit to
MassDEP and EPA a report on the previous year's sampling program. The report shall
include a summary of the receiving water sampling data collected over the past calendar
year, including sampling locations and parameters, and comparisons between results during
wet and dry weather, a characterization of rainfall events for which wet weather sampling
was done, and an assessment of the water quality impacts of CSO and non-CSO sources.
C. CSO Performance Assessment
1. CSO Activations and Volumes
By December 31, 2021, MWRA shall submit the results of the CSO Performance
Assessment to EPA and MassDEP, documenting the level ofCSO control achieved through
implementation of the LTCP throughout the CSO planning area, in regard to CSO activations
and volumes in the Typical Year, relative to the Second Stipulation levels of control (Exhibit
B). and shall also post the Assessment Report on its website. During the course of
completing this work, MWRA shall also undertake the following actions:
a) Progress Reports: MWRA shall submit progress reports to MassDEP and to EPA,
and shall post the reports to the MWRA website in accordance with the following
schedule:
1. Progress Reports # 1, 2, and 3 shall be submitted and posted on or before
October 31, 2019, and together shall be inclusive of all work done for the
CSO Performance Assessment through June 30, 2019;
11. Progress Report #4 shall be submitted and posted on or before April 30. 2020,
and shall be inclusive of all work done for the CSO Performance Assessment
through December 31, 2019;
1 ·Typical Year" rainfall has been the basis for dc,·clopmcnt. re..:onum:ndation and apprm:al oUvlWRXs I.TCP. tht: establishment of the fi:deral
court mandated levels of control. and the assessment of system perfbrmancc toward attainment of the 1. J"CP levels of control. The Typical Year
was developed fwm --l-0 y-:ars of rainfall records ( 1949-1987. plus 1992). and it includes 93 storms with a total precipitation of..f.6.8 inches.
3
111. Progress Report #5 shall be submitted and posted on or before October 31,
2020, and shall be inclusive of all work done for the CSO Performance
Assessment through June 30, 2020;
1v. Progress Report #6 shall be submitted and posted on or before April 30, 2021,
and shall be inclusive of all work done for the CSO Performance Assessment
through December 31, 2020; and
v. Progress Report #7 shall be submitted and posted on or before October 31,
2021, and shall be inclusive of all work done for the CSO Performance
Assessment through June 30, 2021.
Progress Reports shall include a summary of work completed, metering data
collected, integration with MWRA's sewer system model, estimated CSO discharges
from metering data (or model simulations when approved by MassDEP), a discussion
of any locations where metered, or when approved by MassDEP, modeled CSO
discharges appear to exceed Second Stipulation levels of CSO control, and any
measures taken to optimize the Nine Minimum Control actions to further control CSO
discharges.
b) Public Meetings:
1. MWRA shall arrange for public meetings in May 2020 and May 2021, to
present information on the progress of the work and findings to date, and
allow for public input;
11. MWRA shall arrange for a public meeting in February 2022 to present the
findings of the CSO Performance Assessment, and to allow public comment
on the Assessment and its findings; and
111. Notice for the date, time, and location of each public meeting shall be
provided in the Environmental Monitor at least thirty days in advance of each
public meeting.
2. Assessment ofCSO Water Quality Impacts
MWRA shall implement the Receiving Water Model Workplan, dated May 24, 2019 and
revised July 18, 2019, along with the Receiving Water Modeling of Upper Mystic
River/Alewife Brook and Charles River Basin: Work Plan for Stormwater and Combined
Sewer Overflow Monitoring, 2019-2020, dated June 6, 2019 and revised August 27, 2019,
and develop and calibrate a receiving water quality model, and use such model to present
information on the water quality impacts of CSO and non-CSO discharges in the Alewife
Brook/Upper Mystic River watershed.
The Final CSO Water Quality Impact Report shall be submitted to MassDEP and EPA on or
before December 31, 2021, and shall include a description of the data collected and used for
developing and calibrating the model; information on CSO and non-CSO water quality
impacts for a range of design storms and the Typical Year; and a sensitivity analysis showing
the water quality benefits of further pollutant reductions in upstream sources. storm water,
and CSO discharges.
4
D. Notification to the Public of CSO Discharges and Impacts
I. MWRA and the Cities of Cambridge and Somerville shall maintain outfall signs that are
visible both from the shore and from in stream locations for their permitted CSO
discharges. Pursuant to their NPDES Permits, the following language, at a minimum,
shall be included:
WARNING:
WET WEATHER
SEW AGE DISCHARGE
OUTFALL (discharge serial number)
2. MWRA and the Cities of Cambridge and Somerville shall update and maintain
informational signs at John Wald Memorial Park in East Arlington and other public
access locations to be recommended by the permittees and approved by MassDEP in
order to advise the public of CSO discharges and potential public health impacts and to
provide contact information and website links. The text of the notice shall be subject to
prior approval by MassDEP.
3. MWRA and the Cities of Cambridge and Somerville shall issue a joint press release by
April 15 of each year to watershed advocacy groups, local health agents, and newspapers
oflocal circulation in the Alewife Brook/Upper Mystic River watershed, which shall
include general information on CSOs, the location of outfalls in the Alewife Brook/Upper
Mystic River watershed. and potential health risks posed by exposure to CSO events.
4. MWRA, and the Cities of Cambridge and Somerville shall. by December 31, 2020,
develop and implement a CSO Subscriber-Based Notification System to provide CSO
Alert Notifications to any interested parties, which shall include the following
components:
a. A CSO Alert Notification shall be issued no later than 4 hours after becoming
aware ofa CSO event from one or more of the permittee's CSO outfalls, but in no
event later than 12 hours after onset of the CSO discharge, which shall be issued
to: MassDEP, EPA, local boards of health in Cambridge, Somerville, Arlington,
and Medford, the Mystic River Watershed Association, and any person subscribed
to receive such Alert Notifications.
The CSO Alert Notification shall provide. at a minimum, the following
information:
1. Outfall location(s):
11. Approximate time and date of onset of the discharge:
n1. Whether, at the time of notification, the discharge has ceased, and if so,
the approximate time that the discharge ended:
1v. Waters and land areas potentially affected by such discharge;
v. Precautionary measures for the public to avoid health risks from contact
5
with eff1uent; and
v1. Link to the permittee's website for additional information on CSOs and its
CSO abatement program.
Until such time as the Subscriber-based system is in place, the City of Cambridge
shall continue its current practice of providing a CSO Alert email notification to
MassDEP, EPA, local Boards of Health, and the Mystic River Watershed
Association, within 24 hours of a CSO event from one or more of their pennitted
CSO outfalls.
b. MWRA, and the Cities of Cambridge and Somerville shall each establish and
maintain a public website, which shall include, at a minimum, the information
listed below, for their permitted CSO outfalls in the Alewife Brook/Upper Mystic
River watershed. If agreed upon by MWRA and the Cities of Cambridge and
Somerville, this requirement may be met by one entity compiling and posting the
data on their website, and the other entities providing a link on their own websites
to the data.
1. A map showing the locations of the CSO outfalls, correlating to the CSO
outfall numbers included in their respective NPDES Permits;
11. On or before December 31, 2020. instructions on how an interested person
can self-register for the CSO Subscriber-Based Notification System;
111. Within 5 business days of any CSO Alert Notification issued, updated
information on the estimated duration and volume of the CSO discharge
and event rainfall data; and .
1v. Annual lists of the permittees' CSO outfalls within the variance waters
with information compiled on duration and volume of discharges from
each outfall, as well as cumulative discharge volume from all CSOs. Each
annual calendar year summary shall be updated and posted on the website
no later than April 30 th of each year.
E. Other Actions to Minimize CSO Discharges
1. MWRA and the Cities of Cambridge and Somerville shall continue to implement the
Nine Minimum Controls (NMC), as set forth in their respective NPDES Permits and the
Variance conditions, which must include the following components:
a. Proper operation and regular maintenance programs for the sewer system and
the CSOs.
b. Maximum use of the collection system for storage.
c. Review and modification of the pretreatment program to assure CSO impacts
are minimized.
d. Maximization of flow to the POTW for treatment.
e. Prohibition of dry weather overflows from CSOs.
f. Control of solid and floatable materials in CSOs.
g. Pollution prevention programs that focus on contaminant reduction activities.
6
h. Public notification to ensure that the public receives adequate notification of
CSO occurrences and CSO impacts.
1. Monitoring to effectively characterize CSO and the etlicacy of CSO controls.
Any enhancements to the MWRA and community NMC programs identified by
MassDEP or the permittees during the CSO Performance Assessment can and shall be
implemented after obtaining all necessary approvals. providing the enhancements do not
conflict with the overall goals and requirements of the LTCP. as measures to further
reduce CSO discharges so that highest attainable interim etrluent conditions can be
achieved and maintained during the Variance period.
2. Variance Pollutant Minimization Program as required by 40 CFR
l 3 l.14(b)(l )(ii)(A)(3): MWRA, with assistance/support from the Cities of
Cambridge and Somerville, shall implement the Additional System Optimization
measures as set forth in the scope and schedule of actions in attached Exhibit A.
MWRA shall coordinate with the Cities of Cambridge and Somerville to evaluate
the impact of any Additional System Optimization measures on all three systems'
performance. Beginning in 2021 and on or before January 31 of each year until the
end of this Variance, MWRA shall submit to MassDEP and EPA, and shall post on
its website, progress reports on the implementation of the Additional System
Optimization measures. Exhibit A represents the pollutant minimization activities
that MWRA will implement in this variance term.
3. MWRA shall continue to provide technical assistance related to the identification and
removal of Infiltration/Inflow (I/I) to member communities. Where requested by any
member community, or by MassDEP or EPA, MWRA shall provide information from
MWRA metering data. including but not limited to:
a. A system map showing locations ofMWRA metering points;
b. MWRA metering data by each MWRA member sewer community. broken
down into estimates of average monthly sanitary flow, average monthly
infiltration and average monthly inflow; and
c. MWRA metering data by meter subarea correlating to a specific storm event.
4. The Cities of Cambridge and Somerville shall consider use of Green Infrastructure
technologies where feasible to increase stormwater infiltration.
F. Updated CSO Control Planning
On or before April 1. 2022. MWRA, and the Cities of Cambridge and Somerville shall each
submit for MassDEP and EPA review and approval, a scope and schedule for an updated
CSO Control Plan for the CSO outfalls that each permittee owns and operates that discharge
to the Alewife Brook/Upper Mystic River. The updated CSO Control Plan shall conform to
the EPA CSO Policy and MassDEP's 1997 Guidance/hr Abatement olPo/lutionfi-0111 CSO
Discharges. and shall specifically include the following elements:
7
I. A description of the ex isting leve l o f CSO control:
2. An evaluation of the costs and pe rformance ( i.e. , effecti veness in reducin g CSO
discharge frequenc y and/or volume) and water quality improvements achieved by
additional CSO control alternatives, up to and including, e limination of CSO discharges.
For the C ities of Cambridge and Somervi lle, use of Green Infrastructure technologies
shall be conside red. The evaluation of costs and water quality benefits may include the
impacts of storm water di scharges;
3. A public participation plan sufficient to provide for ample opportunities for the public to
be informed about the development of the Plans at critical junctures, a nd to have
opportunities to provide informed comments on the CSO abatement alternatives and
recomme ndations. The scope of the plan, as an e leme nt of full scope of work, shall be
subject to MassD EP review and approval. This plan shall include submittals to comply
with the Massachusetts Environmental Policy Act, 30 I C MR 11.00;
4. An affordability analysis consiste nt with EPA's November 24, 2014 lvlemorandum on
Financial Capability Assessment Framework for i\lfunicipal Clean Water Act
Requirements . along with any other relevant information to assess financial capacity;
5. A Draft Reco mmended Plan, to be submitted to MassDEP and EPA by June 30, 2023,
which achieves compliance with the federal C lean Wate r Act, the federal Water Qua lity
Standards regulations (40 C FR Part I 3 1) a nd the Massachusetts Surface Water Quality
Standards regulations (3 14 CMR 4.00), supporting as needed any recomme ndatio ns for
c hanging the classification of any CSO-impacted receiving waters with Use Attainabi lity
Analyses.
6. A Final Recommended Plan, to be submitted to MassDEP and EPA for review a nd
approval by Decembe r 3 1, 2023 , which responds to comments received on the Draft
Recommended Pla n.
Subject to the conditions inc luded in this Varia nce, MWRA, and the C ities o f Cambridge and
Somerville shall be a uthorized to di scha rge limited CSOs during wet weather events to the
A lewife Brook/Upper Mystic Ri ver Basin.
~ A.! //IL_~
Date Issued Kathleen M. Baskin
Assistant Commissione r
Bureau of Water Resources
Effective Date
8
Exhibit A
MWRA CSO Variance
Additional System Optimization Measures
Below is a summary of the specific additional system optimization measures that MWRA will
undertake during a 5-year variance period beginning September 1, 2019. These activities are
intended to further MWRA ·s goals of improving water quality in the Lower Charles River.
Upper Mystic River, and Alewife Brook. These measures are consistent with the requirements of
40 CFR 131.14, and allow for progress to be made towards attaining designated use(s) and water
quality criteria. Collectively with the other elements of the CSO Variance requirements, these
efforts comprise the Pollutant Minimization Program to be implemented during the course of the
CSO Variance. Additional CSO system optimization efforts and on-going implementation of the
··cso Nine Minimum Controls" will be informed by MWRA's hydraulic model, which is in the
process of being calibrated with extensive flow and overflow meter data being gathered, which
commenced in 2018. MWRA expects the calibration to be complete by the fall of 2019. These
efforts will also be informed by MWRA's updated receiving water quality models, which will be
produced and available in the early years of the variance period.
Mystic River Watershed Project
I. Evaluate alternatives to reduce CSO activation frequency and volume at the Somerville
Marginal CSO Treatment Facility, and associated CSO outfalls SOM007A/MWR205A, and
MWR205, while avoiding any increase in the frequency and volume of CSO discharges at
MWRA's Prison Point CSO Treatment Facility (MWR203), and CSO outfalls CAM0l 7 and
BOS0l 7. Alternatives to be evaluated. at a minimum, will include:
• Construction of dry weather connection reliet/Control from the City of Somerville's
CSO regulator RE071A to MWRA's Somerville-Medford Branch Sewer; and
• Relocation ofMassDOT 1-93 drainage from upstream to downstream of the
Somerville-Marginal facility to reduce the frequency and volume of facility
activations.
The work will need to address heavy trafiic and underground utilities in the project area. and
will also require close coordination with MassDOT. MWRA will develop a Somerville
Marginal CSO Reduction Plan, which will include the outcome of the feasibility study;
preliminary design plans for projects recommended to further reduce CSO discharges at this
facility, and a schedule for final design and construction of recommended facilities.
Construction will proceed unless the feasibility evaluation clearly demonstrates that
construction is technically infeasible, that the project will not provide water quality benefits
through the reduction of CSO volume or frequency. or that the costs. alone or in conjunction
with other activities specified in Exhibit A, would cause widespread social and economic
impact.
MWR205 & SOM007/MWR205A Somerville Marginal CSO Reduction Project, Study
and Preliminary Design
9
Notice to Proceed - December 2020
Study Report/Preliminary Design Submittal to MassDEP for review and approval -
December 2021
Alewife Brook Project
2. MWRA proposes to evaluate maximizing beneficial use of enhanced pumping capacity at
the recently rehabilitated Alewife Brook Pump station to lower wastewater elevations in the
upstream collection system and potentially reduce CSO activations and volumes at upstream
CSO outfalls CAM00I, CAM002, MWR003, and SOM00IA. During the Variance period,
MWRA will assess alternative pumping strategies and expected upstream benefits using the
MWRA's calibrated hydraulic model. Alternatives determined to provide potential benefits
will be tested for a range of storm events. MWRA will develop an Alewife Brook Pump
Station Optimization Report with findings and recommendations, including modeled control
alternatives and testing, and an implementation plan to establish a schedule for any required
programming of automated facility control changes and operator training, which shall
become the standard operating procedure to minimize CSO discharges. Implementation will
proceed unless the feasibility evaluation clearly demonstrates that construction is technically
infeasible, that the project will not provide water quality benefits through the reduction of
CSO volume or frequency, or that the costs, alone or in conjunction with other activities
specified in Exhibit A, would cause widespread social and economic impact.
Alewife Brook Pump Station Optimization Evaluation Project
Notice to Proceed - April 2020
Alewife Brook Pump Station Optimization Report submittal to MassDEP for review and
approval - April 2021
Alewife Brook and Charles River Watershed
3. Using the calibrated hydraulic model and coordinating technical evaluations with the Cities
of Cambridge and Somerville and the Boston Water and Sewer Commission, MWRA will
conduct system optimization evaluations at the remaining active regulators tributary to CSO
outfalls discharging to the Alewife Brook and Charles River watersheds. The MWRA will
then implement recommended modifications to those regulators owned by MWRA and will
provide technical support to member communities in their efforts to implement
recommended modifications to community owned CSO regulators. The MWRA anticipates
evaluating and implementing optimization measures such as regulator closing, overflow weir
modification or raising, dry weather connection relief and flow reallocation opportunities.
System optimization on a regulator by regulator basis is an important component of the Nine
Minimum Control measures. The improved hydraulic model now being calibrated with
extensive metering data will facilitate MWRA's ability to further refine the components of
individual regulators. These refinements are expected to help reduce frequency and volume
of CSO discharges while also protecting against adverse impacts. such as upstream system
IO
flooding, especially in larger storms, or higher CSO discharges at other hydraulically related
outfalls. A preliminary list of tasks is provided below to support the 2-year study and
preliminary design schedule:
• Meeting and coordinating with CSO communities to determine what
modifications/studies they have already performed, areas of concern for
flooding (historic record research), planned community improvements in
upstream systems, recommendations communities may have to modify regulator
structures/shift flows, etc.
• Extending MWRA's hydraulic model into upstream pipe networks if needed to
better assess proposed modification impacts on systems tributary to each
regulator.
• Studying the hydraulics of the existing system for various storm events to look
for opportunities to maximize flows to the wastewater conveyance system
throughout various types of storm events (high intensity short duration, long
duration low intensity, etc.), while maintaining protective relief in larger storms.
• Developing proposed modifications to regulators (weir height adjustment),
additional relief opportunities during large events (e.g., bending weirs), dry
weather connection modifications (increase size, one-way valve control, etc.) to
take advantage of any available hydraulic capacity in the downstream
interceptors.
• Performing model simulations of typical storm events as well as large events
(IO - 25 year recurrence interval) to evaluate proposed modification benefits
and potential adverse impacts.
• Developing and garnering consensus on sewer operation modifications.
• Developing preliminary design of recommended/approved sewer operation
modifications for those which require excavation/significant construction for
modification to the regulators.
Implementation will proceed unless the feasibility evaluation clearly demonstrates that
construction is technically infeasible, that the project will not provide water quality benefits
through the reduction of CSO volume or frequency, or that the costs, alone or in conjunction
with other activities specified in Exhibit A, would cause widespread social and economic
impact.
CSO System Optimization for Alewife Brook and Lower Charles River Basins Project,
Study and Preliminary Design
Notice to Proceed - December 2020
System Optimization Report submittal to MassDEP for review and approval - December
2022
II
EX HIBIT B
LTC P Levels of Control from Second Stipulation
LONG TERM CONTROL PLAN
CSOOUTFALL TYPICAL YEAR
Activation Frequency V olume (l\IG)
.-\LE\YIIT BROOK
CAM00l 5 0. 19
CAM002 4 0.69
M\VR.003 5 0.98
CAM004 To be closed NIA
CAM400 To be closed N:'A
CAM401A 5 1.61
C.-\1'v!401B 7 2. 15
SOMOO lA 3 1.67
S0}.• 1001
SOM002A
Closed
Clo,ed
NIA
NlA
SOM003 Closed NlA
Sm.• 1004 Clo,ed NIA
TOT..\L 7.29
rPPER ~IYSTIC Rl\"ER
SO:M007•.\:'1.f\VR.205A (Somerville l\.farwial) 3 3.48
SOM007 Closed NIA
TOT..\L 3.48
~IYSTIC I CHELSEA. CO:\TI.U::'-CI:
}.,[\VR105 (Somerville Ma.ntinal) 39 60.58
BOS013 4 0.54
BOS014 0 0.00
BOS015 Closed NIA
BOS0l 7 I 0.02
CHE002 4 0.22
CHE003 3 0.04
CHE004 3 0.32
CHE008 0 0.00
TOT. .\L 61.i1
CPPER D,":\"ER HARBOR
BOS009 5 0.59
BOS0!0 4 0.7'.?
BOS0l2 5 0.72
BOS019 ) 0.58
BOS050 Closed N/A
BOS052 Clo,ed N/A
BOS057 I 0.43
BOS058 Closed NIA
BOS060 0 0.00
~fWR.203 (Prisou Point) 17 243.00
TOT. .\L ~46.0.t
12
LONG U:Rl "\I CONIROL PLA1 ~
CSOOUTFALL TYPICAL YEAR
Volume (l\IG)
LOWER D.:-IR H.-\RBOR
Activation Frequency
BOS003 4 2.87
BOS004 5 1.84
BOS005 1 0.01
BOS006 4 0.24
BOS007 6 1.05
TOT..\!. 6.01
CO'.'iSTITI:-rIO'.'i BL \.CH
MWR:207 Closed N!A
TOT..\!. 0.00
FORT POD.1 CH..\.'>:-IL
BOS062 I 0.0 1
BOS064 0 0.00
BOS065 I 0.06
BOS068 0 0.00
BOS070
BOS070/DBC 3 2.19
UPPS 17 71.37
BOS070/RCC l 0.16
BOS072 0 0.00
BOS073 0 0.00
TOT..\!. 73.S9
RESER\ID CH..\. "\:-"EL
BOS076 3 0.91
BOS078 3 0.18
BOS079 I 0.04
BOS080 3 0.15
TOT..\!. u s
'.'iORTHER'i DORCHESTER B..\Y
BOS08! 0 / 15 vear N/A
BOS082 0 : 15 year NlA
BOS083 0 , 15 year NIA
BOS084 0 , 25 vear NIA
BOS085 0 / 15 year N/A
BOS086 0 I 15 year NIA
BOS087 0 25 vear Ni.A
TOT..\!. 0.00
SOl"THI:R., DORCHESTER B..\Y
BOS088 To be closed N/A
BOS089 (Fox Point) To be closed Ni.A
BOS090 (Commercial Poi.nc) To be closed Ni.A
TOT.U 0.00
13
CSOOUTFALL
LONG TERi\I CONTROL PLAL"l
TI'PICAL 'YEAR
Activation Frequency Volume (i\IG)
CPPER CH..\RLES
BO5032 Closed NIA
BOS033 Closed NIA
CAM005 3 0.84
CM1007 I 0,03
CM1009 2 0.01
CM1011 0 0.00
TOT.\L o.ss
LOWER CH.\RI.IS
BOS028 Closed NIA
BOS042 Closed NIA
BOS049 To be closed NIA
CMf01 7 1 0A5
'.'vfWR0 l 0 0 0.00
1·£ \VR.018 0 0.00
:M\VR.019 0 0.00
}.,fWR.010 0 0.00
'.\-fWR.02 1 Closed NIA
:MWR.022 Closed N/A
MWR201 (Cottage Faim) 2 6.30
MWR023 2 0.13
SOM0!O Closed N/A
TOT.\L 6.SS
XEPOXSET ImIR
BO5093 Closed NIA
BOS095 Clo,ed NIA
TOT.\L 0.00
BACK 8.-\Y rrxs
BO5046 2 5.38
TOT.\L ::.38
14