Technical Memorandum:
Recommendations to adapt Ambient
Monitoring and Contingency Thresholds to

monitor potential ecological risks to
Massachusetts Bay resulting from the Deer

Island Discharge

EPA/600/R-22/064

Review Team

James Hagy1, CEMM/ACESD
Tim Gleason1, CEMM/ACESD
Autumn Oczkowski1, CEMM/ACESD
Avery Tatters2, CEMM/GEMMD
Yongshan Wan2, CEMM/GEMMD

1U.S. Environmental Protection Agency, Center for Environmental Measurement and Modeling,
Atlantic Coastal and Environmental Sciences Division, Narragansett, Rl

2U.S. Environmental Protection Agency, Center for Environmental Measurement and Modeling,
Gulf Environmental Measurement and Modeling Division, Gulf Breeze, FL

August 4, 2022

1


-------
Purpose

To assist U.S. Environmental Protection Agency (EPA) Region 1 in addressing questions and
concerns related to reissuance of the administratively continued National Pollution Discharge
Elimination System (NPDES) discharge permit for Massachusetts Water Resources Authority's
(MWRA) Deer Island Treatment Plant (DITP), EPA Region 1 requested that a review team from
EPA's Office of Research and Development evaluate the data and analyses included in recent
MWRA water column monitoring reports. The charge to the team was to evaluate how these
data and analyses address the potential for the discharge to cause environmental effects that
could harm North Atlantic right whales (Eubalaena glacialis) or other threatened and
endangered species that utilize habitats in Massachusetts Bay. This is addressed in a document
entitled "Technical Memorandum: Review of MWRA Water Quality Monitoring Results to
Address Potential for Harmful Effects of the Deer Island Discharge on Threatened and
Endangered Species in Massachusetts Bay."

EPA Region 1 separately requested that the review team consider what if any changes the
review team would recommend to the ambient monitoring plan and contingency plan required
under the DITP NPDES discharge permit to better monitor environmental responses or impacts
potentially related to the discharge. This document addresses this objective.

Disclaimer

The views expressed in this document are those of the review team members and do not
necessarily represent the views or the policies of the U.S. Environmental Protection Agency.
This document has been reviewed in accordance with U.S. Environmental Protection Agency
policy and approved for distribution.

Suggested Citation

Hagy, J., T. Gleason, A. Oczkowski, A. Tatters, and Y. Wan. 2022. Technical Memorandum:
Recommendations to adapt Ambient Monitoring and Contingency Thresholds to monitor
potential ecological risks to Massachusetts Bay resulting from the Deer Island Discharge. US
Environmental Protection Agency, Office of Research and Development, Narragansett, Rl.
EPA/600/R-22/064. 6 pp.

Key Observations and Recommendations

1. MWRA's Ambient Monitoring Program was well-conceived to address its objectives based
on substantial technical and public input and has been reviewed and modified as old
questions were resolved and new questions emerged.

Several advisory committees provide regular review and oversight to MWRA's monitoring
program and, along with MWRA itself, have enabled the ambient monitoring plan to remain

2


-------
relevant, up to date in purpose and methodology, and responsive to the public interest. These
processes for review and modification of the monitoring program appear to function as
intended and should continue. Although continuity is a priority for long-term monitoring,
monitoring activities that provide data that no longer serve an important scientific need could
be reduced, providing new opportunities to prioritize and address the most current issues. That
said, routine monitoring and reporting for parameters needed to track and diagnose any issues
with plant operations should not be reduced. We did not review potential changes to metals,
organic contaminants, or any other parameters that are not principally bio-stimulatory (i.e.,
nutrients) and thus related to pathways we identified in our first memorandum as having
potential to impact North Atlantic right whales.

2.	If nutrient-related impacts of the discharge were to emerge in the context of a changing
biological regime in Massachusetts Bay, these would most likely appear as incipient trends in
the pattern or distribution of water quality or biological variables. Analysis of new data
would better detect these trends if organized around this expectation.

The MWRA water column reports emphasize improvements in Boston Harbor water quality and
accompanying acceptable and relatively subtle water quality changes in Massachusetts Bay.

This evidence of the overall success of the wastewater divergence is now well-documented and
broadly accepted. Therefore, future reports could emphasize identifying and quantifying trends
and emerging issues or threats. Although the reports do quantify changes, trend analysis does
not appear to receive sufficient focus. Sophisticated analytical methods (e.g., Generalized
Additive Models) are available to describe temporal trends in the context of complex seasonal
and other drivers of short-term variability (Harding et al. 2016, Beck et al. 2018, 2022) while
even more established methods (Hirsch et al. 1982) would give improved insight. These
methods have been applied successfully to evaluate similar data and questions for coastal
systems such as Chesapeake Bay, San Francisco Bay, and Tampa Bay. These methods should
also be used to better quantify and understand evolving water quality and biological conditions
in Boston Harbor and Massachusetts Bay.

3.	Harmful algal blooms (HABs) are not a new threat to the ecology of Massachusetts Bay, but
the threat of HABs is evolving. Scientific uncertainty related to toxin exposure could be
reduced by improving monitoring of algal toxins in open-water plankton, which are most
likely to be transferred to North Atlantic right whales. Similarly, improved monitoring of the
timing, sources, and pathways of toxin exposure would reduce scientific uncertainty
regarding the current or future influence of the discharge on algal toxin exposure.

MWRA's monitoring program demonstrated its ability to identify and quantify harmful algal
bloom species by documenting Alexandrium, Karenia, Dinophysis, and other HAB species in
recent years (Libby et al., 2020). MWRA's Rapid Response Survey approach to monitoring
Alexandrium blooms (Libby, 2006) can monitor if an Alexandrium bloom is likely and then track

3


-------
its spatial distribution and progression if a bloom occurs. One shortcoming is that the triggering
event for rapid response surveys is presence of toxic HABs in shellfish in nearshore habitats.
While a valuable indicator of coastal HAB toxicity, this measure could potentially miss the
presence of HABs and associated toxicity in planktonic food webs in open water habitat.
Additionally, although obtaining early warning from toxin observed in Maine and New
Hampshire is reasonable in view of experience over the past 20 years, this may no longer
adequately address the potential for blooms originating locally since the recent establishment
of an Alexandrium cyst bed in Massachusetts Bay. Therefore, the potential to track toxin
exposures in open water, and to potentially use these data as triggers for surveys tracking
Alexandrium blooms, along with potential impacts of Alexandrium blooms to C. finmarchicus
density to determine potential disruption to the food chain for North Atlantic right whale,
should be considered. One approach that could be used is solid-phase adsorption toxin tracking
(SPATT; Kudela, 2017; Lane et al. 2010; Onofrio et al., 2021). Deploying SPATT resins is a cost-
effective, integrative (i.e., time-averaging), and proven approach for monitoring exposure to a
variety of algal toxins in the natural environment.

4. MWRA could efficiently reduce scientific uncertainty by identifying and implementing
options to improve and expand regional cooperation and coordination of monitoring of
Massachusetts Bay and surrounding systems.

At the inception of the ambient monitoring program, MWRA noted the relationship between
scale of monitoring and the potential for monitoring programs to contribute to management
objectives, adapting information from the National Research Council (Table 1 in MWRA, 1991).
Therein, MWRA noted that certain effects such as permit compliance, source-specific effects,
and public health risks could be best addressed by site-specific monitoring. Many of these
issues have been addressed or significantly resolved over the past several decades by the
ambient monitoring program. This makes other issues relatively more important, including
possible direct and indirect risks to living resources such as North Atlantic right whales,
cumulative effects of multiple stressors, and modulation of effects by natural variation. As
MWRA (1991) noted, these effects may be addressed better by regional monitoring and
analysis than site-specific monitoring. Interactions between regional environmental condition
and wastewater outfalls are present in other coastal areas with significant wastewater
discharges. One approach used to address this by the regulated community is to participate in
innovative regional monitoring cooperatives to improve monitoring while sharing the
associated expense and effort with other stakeholders. Examples include the San Francisco Bay
Regional Monitoring Program (SFEI 2022) and the Southern California Bight Regional
Monitoring Program (SCCWRP 2022). MWRA already provides supplemental support to regional
monitoring efforts such as the Gulf of Maine Ocean Observing System (MWRA, 2021), while
also leveraging data from non-MWRA sources such as toxicity monitoring by the Massachusetts
Division of Marine Fisheries and ocean color sensing from NASA's Moderate-resolution imaging
spectroradiometer (MODIS). We recommend evaluating how expanded regional cooperation,

4


-------
coordination, and cost sharing could support improved monitoring and analysis of emerging
concerns.

5. The contingency plan approach could be more effective if it was revised for some
parameters to better reflect expected temporal and spatial biological response patterns to
nutrient discharges, including stimulation of HABs.

MWRA's contingency plan "specifies numerical or qualitative thresholds that could
suggest that effluent quality or environmental conditions may be changing or might be likely to
change in the future" (MWRA, 2021). The contingency plan calls for responses to individual
exceedances of caution or warning levels to identify potential causes associated with the
discharge and decide if plant operations should be adjusted. Although this approach is likely
sensible for many pollutants, we suggest that, if not already addressed, this approach could be
modified in application to chlorophyll-a levels or HABs, which are associated with a
convergence of favorable oceanographic conditions and would be unlikely to occur as a short-
term consequence of a change in plant operations alone. For example, caution levels could
potentially be based on a departure of multiple observations from seasonally expected
patterns.

References

Beck, M. W., Jabusch, T. W., Trowbridge, P. R., & Senn, D. B. 2018. Four decades of water

quality change in the upper San Francisco Estuary. Estuarine, Coastal, and Shelf Science,
212,11-22. doi:10.1016/j.ecss.2018.06.021

Beck, M. W., de Valpine, P., Murphy, R., Wren, I., Chelsky, A., Foley, M., & Senn, D. B. 2022.
Multi-scale trend analysis of water quality using error propagation of generalized
additive models. Science of the Total Environment, 802, 149927.
doi:10.1016/j.scitotenv.2021.149927

Harding, L. W., Gallegos, C. L., Perry, E. S., Miller, W. D., Adolf, J. E., Mallonee, M. E., & Paerl, H.
W. 2015. Long-Term Trends of Nutrients and Phytoplankton in Chesapeake Bay.
Estuaries and Coasts, 39(3), 664-681. doi:10.1007/sl2237-015-0023-7

Hirsch, R. M., et al. 1982. Techniques of trend analysis for monthly water quality data. Water
Resources Research 18(1): 107-121. doi: 10.1029/WR018i001p00107

Kudela, R. M. 2017. Passive Sampling for Freshwater and Marine Algal Toxins. 78, 379-409.
doi:10.1016/bs.coac.2017.08.006

5


-------
Lane, J. Q., Roddam, C. M., Langlois, G. W., & Kudela, R. M. 2010. Application of Solid Phase
Adsorption Toxin Tracking (SPATT) for field detection of the hydrophilic phycotoxins
domoic acid and saxitoxin in coastal California. Limnology and Oceanography: Methods,
8(11), 645-660. doi:10.4319/lom.2010.8.0645

Libby, P. S. 2006. Standing Survey Plan: Rapid Response Alexandrium Survey. Report 2006-05.
Retrieved from Boston, MA: http://www.mwra.com/harbor/enquad/pdf/2006-05.pdf

Libby, P. S., Borkman, D. G., Geyer, W. R., Turner, J. T., Costa, A. S., Taylor, D. I., . . . Codiga, D.
2020. 2019 Water column monitoring results. Retrieved from Boston:
http://www.mwra.com/harbor/enquad/trlist.html

M WRA. 1991. Massachusetts Water Resources Authority effluent outfall monitoring plan phase
I: baseline studies. Report 1991-ms-2. Retrieved from Boston, MA:
http://www.mwra.com/harbor/enquad/pdf/1991-ms-02.pdf

MWRA. 2021. Ambient monitoring plan for the Massachusetts Water Resources Authority

effluent outfall revision 2.1. August 2021. Report 2021-08. Retrieved from Boston, MA:

http://www.mwra.com/harbor/enauad/pdf/2021-08.pdf

Onofrio, M. D., Egerton, T. A., Reece, K. S., Pease, S. K. D., Sanderson, M. P., lii, W. J., . . . Smith,
J. L. 2021. Spatiotemporal distribution of phycotoxins and their co-occurrence within
nearshore waters. Harmful Algae, 103, 101993. doi:10.1016/j.hal.2021.101993

SFEI 2022. San Francisco Estuary Institute, Projects related to the Bay Regional Monitoring

Program, accessed 6/6/2022. https://www.sfei.org/programs/bay-regional~monitoring~
program

SCCWRP 2022. Southern California Coastal Water Research Project, Southern California Bight
Regional Montioring Program, accessed 6/6/2022.

https://www.sccwrp.org/about/research-areas/regional-monitoring/southern-
california-bight-regional-monitoring-program/

6


-------