NPDES Permits in New England
Inter-agency Advisory Committee (IAAC) Meeting
Thursday, October 14, 1999, 12:30 to 3:00 PM,
Members Present: : Salvatore Testaverde, NMFS (chair); Russ Isaac, MADEP, Matt Liebman, EPA; Steve Lipman, MADEP alternate; Jan Smith, MCZM alternate, and Jack Schwartz, MADMF.
Observers: Peter Borrelli, Center for Coastal Studies; Cathy Coniaris, OMSAP/PIAC/IAAC Assistant; Patty Daley, Cape Cod Commission; Gillian Grossman, Save the Harbor/Save the Bay; Mike Mickelson, MWRA; Andrea Rex, MWRA; Larry Schafer, observer; Mark Silver, Center for Coastal Studies; and Grace Vitale, MWRA..
SUMMARY OF ACTION ITEMS
- S. Testaverde and J.Schwartz will prepare a letter to EPA/MADEP outlining IAAC's OMSAP charter questions and proposed revisions.
- S. Testaverde will present an overview of NMFS' right whale related activities at the next IAAC meeting.
IAAC approved the summary of the May 17, 1999 meeting with no amendments (two members who did not attend abstained).
OMSAP CHARTER DISCUSSION
S. Testaverde recounted the charter discussion from the May 1999 IAAC meeting. The committee had voted and approved the following PROPOSED IAAC MISSION STATEMENT: "The committee will advise the OMSAP, EPA and MADEP on scientific, technical and/or regulatory matters related to discharges from and operations of the MWRA system outfalls that may directly or indirectly affect Boston Harbor, Massachusetts Bay, and Cape Cod Bay. The IAAC may review or evaluate other environmental matters as necessary."
IAAC also discussed several other potential changes to the OMSAP charter but did not vote to approve them. S. Lipman reiterated G. Haas' comments from the May meeting. [Excerpt from May meeting summary: "G. Haas disagreed with this proposed revision (to the IAAC mission) since OMSAP is the group that advises EPA/MADEP on scientific and technical issues. He also pointed out that IAAC includes representation from EPA and MADEP and thus does not have to formally advise those agencies."]
R. Isaac pointed out that the original mission of IAAC was to respond to OMSAP questions on regulatory issues and not to advise EPA and MADEP directly. S. Testaverde stated that at the May meeting, most members felt that the IAAC mission in the OMSAP charter was to narrow. He feels that there should be a broader IAAC mandate so that we can take advantage of the scientific expertise of IAAC members.
J. Schwartz explained that when the Outfall Monitoring Task Force (OMTF) was dissolved and re-structured into OMSAP/IAAC/PIAC, EPA and MADEP were in the process of developing a very unique permit. Everyone knew that they were on untested grounds and a lot of discussion focused on IAAC's role. He feels that if IAAC is to deal only with regulatory questions, then there is no point for the group to meet. He suggested having contact information available for OMSAP and no IAAC meetings, unless the group was given a broader mandate.
M. Liebman clarified that there are two issues regarding the proposed mission: whether to broaden the scope of IAAC's charge to include advising on scientific issues, and whether to report to EPA and MADEP in addition to OMSAP. He thinks that one benefit of IAAC is that it allows for a group of agencies to make a statement instead of individual agencies, but if "who" to advise becomes a sticking point, then IAAC should just advise OMSAP. He agrees that the IAAC mission should be broadened.
S. Testaverde feels that OMSAP will rarely call on IAAC for advice so the group will have to determine its own meaningful issues to discuss. M. Liebman pointed out that the committee can give advice without being asked by OMSAP. S. Testaverde agreed and added that meetings also provide a platform for the committee to discuss issues the group thinks should be explored. R. Isaac thinks IAAC should ask for clarification from EPA/MADEP on the committee's role. He agreed that IAAC should not advise EPA/MADEP. If EPA/MADEP decide to keep the original mission, then he agrees that IAAC should be a standing committee.
J. Schwartz asked whether the OMTF was dissolved because the agency employees were advising agency upper management from an independent group. R. Isaac replied yes, and added that there were also non-scientists on the OMTF from environmental interest groups who had a say in scientific decision-making. Everyone agreed to form a science panel that provided technical recommendations whose membership was composed of well-respected independent experts.
ACTION: S. Testaverde and J. Schwartz will draft a letter to EPA/MADEP. The letter will include the proposed revised IAAC mission, other proposed changes to the OMSAP charter, and three questions - who does IAAC advise, who has authority to make charter changes, and does IAAC advise only on regulatory matters?
NITROGEN REMOVAL TECHNOLOGIES
Grace Vitale (MWRA) gave a brief presentation on current technologies for nitrogen removal (NR). The NPDES permit requires that MWRA maintain a comprehensive technical survey of effective treatment technologies for NR applicable to the Deer Island treatment facility which is updated at least annually for the duration of the permit. This process is designed to facilitate the speedy selection and implementation of NR technology if deemed necessary. In addition, MWRA must implement a monitoring program to characterize the quality of wastewater streams within the treatment plant in order to produce data that would facilitate the selection of NR technology and facility design, if needed. This monitoring plan will be submitted to EPA, MADEP, and OMSAP within 90 days of the effective date of the permit for approval.
The various treatment alternatives are divided into three categories: physical, chemical, and biological. Examples of physical and chemical treatment include ammonia stripping, ion exchange, breakpoint chlorination, and lime addition. Biological treatment involves nitrification and denitrification. Nitrification is the biological conversion of ammonium to nitrate that occurs under oxidative (aerobic) conditions. Denitrification is the reduction of nitrate to nitrite to nitrogen gas by bacterial action (anaerobic). Nitrification technologies can employ suspended growth, attached growth, aerated filters, fluidized bed reactors, or land treatment using wetlands and ponds. Denitrification technologies include submerged packed bed reactors, fluidized bed reactors, or deep bed filters.
Biological nitrogen removal is preferred for municipal treatment plants. Among the things that MWRA must consider when selecting a treatment alternative are: cost effectiveness, land constraints, power availability, year-round or seasonal treatment, form and concentration of nitrogen compounds, effluent limits, compatibility with existing treatment processes, reliability, and flexibility.
G. Vitale described the pros and cons of the alternatives that have been evaluated for Deer Island. At this time, the "candidate" which MWRA recommends is nitrification using biological aerated filters and denitrification using fluidized bed reactors. These two processes would require 3.4 acres, which is available on Deer Island. Effluent treated with these methods would decrease from approximately 10-20 mg/L total nitrogen to about 3-4 mg/L.
G. Vitale then briefly described MWRA's pre-draft of the effluent monitoring program which will measure nutrients in the influent, primary effluent, secondary effluent, and return streams. MWRA will continue to monitor the emergence of new technologies and experience gained on treatment systems, especially those that are used by cold-weather wastewater treatment plants.
J. Schwartz asked what the approval process is once the NR plan is in place. S. Lipman replied that any changes in technology/operations must be approved by MADEP. G. Vitale added that MWRA has to prove that the methods being proposed will decrease nitrogen by a certain amount to MADEP. S. Lipman suggested that the pilot plant be used to test these various methods.
POLYMER USE IN SECONDARY TREATMENT
S. Testaverde gave a primer on polymers and their use in secondary treatment to reduce total suspended solids (TSS) and biological oxygen demand (BOD) during high flow storm events. Several years ago, EPA/MADEP determined that MWRA need not build secondary battery D because both flows and solids were lower than originally projected - this saved ratepayers $200 million. [To assure that the MWRA would not violate TSS or BOD under high flow conditions, EPA/MADEP required MWRA to use polymer if a violation appeared imminent, but MWRA never planned to use polymer on a regular basis (Maury Hall, MWRA, personal communication).] NMFS is concerned about polymer toxicity testing and the possible effects of polymers on the environment.
A polymer, or polyelectrolyte, is a high molecular weight, long-chained substance formed either naturally or synthetically. Polymers are classified by molecular weight, length of polymer chain, type of charge [neutral, anionic (-), and cationic (+)], and charge density. They are used to "polish" effluent by improving the removal of solids. Polymers are also used as "sludge conditioners" and are very expensive to use. [MWRA does not plan on using polymer at all. The conditions under which MWRA could use them, very high flows, occur 8 to 15 days per year (M. Hall, personal communication).]
The use of polymers in secondary treatment involves two processes:
coagulation and flocculation. [The following definitions are from
Coagulation is the clumping together of very fine particles into larger particles caused by the use of chemicals (coagulants). The chemicals neutralize the electrical charges of the fine particles and cause destabilization of the particles. This clumping together makes it easier to separate the solids from the water by settling, skimming, draining, or filtering. Flocculation is the gathering together of fine particles in water by gentle mixing after the addition of coagulant chemicals to form larger particles.]
Polymer application was required in the MWRA Court Order. MWRA will use polymers when: (1) effluent threatens to violate its NPDES permitted level for average TSS (45 mg/L); (2) at high flows greater than 540 mgd for more than 8 hours; and (3) when solids appear to be flushing into effluent. S. Testaverde believes that the major problem with polymer use is that there is no method to detect polymer in effluent [since polymer is a proprietary mixture of several compounds (M. Hall, personal communication)]. The NPDES permit requires that MWRA minimize the use of polymer in secondary treatment, test new polymers using standard test species, and report the detailed chemical properties of all polymers used [see page 6 of the permit]. The polymer Percol-789 can be dosed at up to 2 mg/L, most of which presumably settles out. S. Testaverde believes that MWRA will have to add more than 2 mg/L to achieve desired results. [MWRA believes that dosing less than 2 mg/L would be sufficient for effective effluent "polishing" (M. Hall, personal communication).] MWRA continues to test new polymers that may be cheaper, better, or less toxic.
MWRA effluent is typically negatively charged and therefore requires a cationic polymer that can be toxic and biologically harmful when used in excess. S. Testaverde quoted from a letter to MWRA from Allied Colloids, dated July 14, 1995 that "cationic (+) polyacrylamides demonstrate appreciable toxicity at moderate doses". Results from toxicity testing using polymer and effluent varied greatly. Older test results found that cationic polymers are acutely toxic at about 2 to 3 ppm in pure water, however, in effluent, there is less toxicity due to the absorption/attachment of polymer and particles. Acute toxicity was reduced by adding solids to adsorb polymers (Biesinger, et al., 1976). However, there are no methods to measure adsorption rates or polymer in effluent.
S. Testaverde showed MWRA toxicity test results for mysid shrimp (acute), lobster larvae (acute), and sea urchin fertilization (chronic). Lobsters larvae were not good test organisms due to high variability in the control survival. Overall, S. Testaverde feels that the polymer toxicity testing results were unclear.
M. Liebman asked what form the polymer is in when it is added. S. Testaverde replied that it is a slippery powder [or liquid (M. Hall, personal communication)]. M. Liebman asked if polymers remove suspended solids using a charge process. S. Testaverde replied that it is a chemical (bonding) and physical (gravity) removal of suspended solids. R. Isaac added that polymers are more efficient at removing very fine particles. Since less is needed compared to other settling compounds, less sludge is created. A. Rex asked if any other wastewater treatment plants have reported environmental problems due to polymer use. S. Testaverde replied that he does not think anyone is looking. He mentioned that he did review some research that showed an impact of positively charged polymers on minnows and sea urchin eggs. He feels that polymers are very effective in reducing TSS and he would be comfortable with their use if more benign types could be developed.
FOOD WEB MODEL SCOPE OF WORK DISCUSSION
P. Daley briefly described Barnstable County Science Advisory Panel's (BCSAP) alternate proposal to MWRA's Food Web Model Scope of Work (FWMSOW). The BCSAP has not finalized the proposal to date. They met to discuss the problems and complexities with food web modeling and attempted to develop a way to address what they see as the potential impacts from the outfall, particularly on right whales. They have developed a food chain concept (not a model) which has three steps and three general hypotheses. The first step is that nutrients from the effluent may affect or change phytoplankton composition and abundance. The second is that a change in phytoplankton may affect zooplankton composition and abundance, and lastly, a change in zooplankton may affect right whales. The BCSAP intends to include several assertions as part of each "step" of the chain referenced from the literature. They believe that the purpose of a food web model scope of work is to look at contingencies and uncertainties. This proposal will be presented in greater detail to OMSAP at their October 26, 1999 meeting. [UPDATE: The BCSAP postponed the presentation of this proposal and the OMSAP meeting was also postponed.]
L. Schafer asked if there are any other species that would be better indicators of the state of the Bays. P. Daley replied that humpback whales may be a better indicator species but since they feed at higher trophic level, developing a food web model for them is much more complex. The focus is on right whales because of their endangered status. L. Schafer believes that measurements of right whale numbers could vary quite a bit due to their scarcity. That is why he feels that a more common species would be a better indicator. S. Testaverde believes that right whales are a better indicator species. Since only about 300 right whales remain, it would be a "red flag" if they did not visit Cape Cod Bay one year. On the otherhand, humpback whales are not as good of an indicator species since they number around 10,000-15,000. L. Schafer disagreed and feels that since there are so few right whales, a few fatal shipstrikes would throw the monitoring data off. S. Testaverde said that if right whales disappear from a critical habitat [Cape Cod Bay], and if it was determined that the outfall actually caused right whales to leave a critical habitat, MWRA will have violated the Endangered Species Act. L. Schafer agreed but feels that blaming the outfall is a big "if". S. Testaverde believes that NMFS would examine this carefully but thinks that it is up to MWRA to defend themselves from any accusations.
P. Daley pointed out that the BCSAP is examining the food web from the "bottom-up", not the "top-down". In other words, instead of examining the right whale population for changes due to the MWRA outfall, the BCSAP is trying to test the hypothesis that the MWRA outfall could cause changes in the ecosystem that might affect right whales. Though the BCSAP and Cape Cod Commission would like to see additional monitoring in Cape Cod Bay, the FWMSOW is only a paper exercise to help inform the monitoring program on what needs to be looked at more closely.
M. Liebman asked P. Daley what the BCSAP will ask of OMSAP. P. Daley replied that they are not convinced that MWRA's current proposal carefully looks at the dynamics between these different trophic levels. In addition, the scope of work [flowchart] stops moving forward if there is no existing data to prove a connection between the outfall and changes in the environment. She hopes that OMSAP adopts a scope of work that establishes a set of hypotheses showing the interconnections that may be influenced by the outfall and in turn would direct the monitoring program towards looking at those interconnections.
R. Isaac asked S. Testaverde which risks for the right whale population (e.g. drift nets, collision with ships, endocrine disrupters, etc.) are being studied, and what is the biggest risk factor identified to date. S. Testaverde replied that all risks are being studied, with the largest risks to right whales being entanglement and ship strikes. Right whales are monitored every year in Cape Cod Bay by the state of Massachusetts, USCG, and NMFS, and there is a mandatory ship reporting system adopted by the international community for Cape Cod Bay, as well as Georgia and Florida. ACTION: R. Isaac requested an overview of NMFS' right whale-related activities. S. Testaverde agreed to present this at the next IAAC meeting. M. Mickelson suggested that those interested review the report by J. Kelly et al. (1998) which discusses a "bottom-up" approach [Kelly JR, Davis CS, Cibik SJ. 1998. Conceptual food web model for Cape Cod Bay, with associated environmental interactions. Boston: Massachusetts Water Resources Authority. Report ENQUAD 98-04. 9 p. Available at http://www.mwra.state.ma.us/harbor/enquad/pdf/98-04_enquad_report.pdf]. Included at the end of the Kelly et al. report are Robert Kenney's (URI/OMSAP) comments that included a diagram of the factors affecting right whale occurrence in Cape Cod Bay.
P. Borrelli feels that one of the reasons why the right whale does play such an important role in this food web analysis is that there are no more than 350 right whales left. Over the past 12 years, the Center for Coastal Studies (CCS) has seen as many as 100 right whales (one-third of the population) visit Cape Cod Bay each year over a 3-4 month period and of the total population, approximately two-thirds of all animals have been observed in Cape Cod Bay. Thus, relatively speaking, these numbers show that there are relatively many right whales that can be used as indicators. It is also important to realize that the right whales visit Cape Cod Bay because of the dense zooplankton patches which are found almost no where else. The CCS is prepared to hypothesize that the feeding habitat in Cape Cod Bay is unique to the species in the western north Atlantic rivaling the Bay of Fundy and any other known habitat. If this unique environment is disturbed or diminished in any way, it could be catastrophic for the right whales. The CCS is not implying that there is a causal relationship to the MWRA outfall, but certainly, the argument would be to take a cautionary role.
R. Isaac asked how long right whales stay this area. P. Borrelli replied that they are feeding in this area from December to April. M. Mickelson pointed out that Stormy Mayo (CCS) said that there are also zooplankton patches in the Great South Channel and that right whales are able to obtain three times their food requirement in while feeding in Cape Cod Bay. R. Isaac asked if the right whales feed on a very restricted diet. P. Borrelli replied that yes, their diet is very restricted, much more restricted than previously thought. Right whales prefer specific copepods - Calanus finmarchicus. The CCS is about a month away from publishing results on this.
L. Schafer still believes that there is a good chance that MWRA will be blamed for something it is not causing. For example, what if a smaller copepod dominates after the new outfall goes on-line causing right whales to go elsewhere. P. Borrelli replied that that would be an issue NMFS would have to respond to since they administer the Marine Mammal and the Endangered Species Acts. L. Schafer pointed out that it could take ten years or more before enough data is definitively collected which proves that MWRA was to blame. P. Borrelli agreed. S. Testaverde thinks that if there were such a large impact on right whales, the Secretary of Environmental Affairs would have to weigh the issue in a quicker time frame. He feels that there are not enough sampling stations within Cape Cod Bay to determine MWRA liability in that scenario.
P. Borrelli stated that the CCS just completed a project design for a collaboration among scientists from Georgia Tech, Boston University, U. Rhode Island, and the CCS. The project is limited in scope and is based on stable nitrogen isotope tracking in which 20 CCS stations in Cape Cod Bay are sampled (locations coincide with historical right whale/zooplankton stations). Stations will be sampled every month (with two months sampled twice). MWRA data will also be studied. The CCS hopes to determine sampling methodology, locate funding, and begin sampling soon so there can be data from both before and after the outfall goes on-line. M. Mickelson feels that the CCS is well positioned to conduct this study since they have the historical record. They would do a better job of finding patches instead of the MWRA Outfall Monitoring Program since in order to find a patch, it is best to first find whales [the CCS studies whales extensively]. S. Testaverde said that NMFS would like to enter a partnership but that [funding would not be available in time for baseline measurements].
M. Mickelson pointed out that J. Montoya had said that the stable nitrogen isotope method has approximately the same sensitivity as salinity measurements and thus will not be able to track the effluent outside of the nearfield. P. Daley disagreed and thinks that this study would be worth the effort because of the potential risk to the right whales. She believes that the main purpose of the FWMSOW is not to establish blame on the MWRA but rather to help us better understand the system.
S. Testaverde asked what the latest outfall startup date was. M. Mickelson guessed March 2000 though there is no official date due to the ongoing investigation of the accident in the outfall tunnel.
Minutes from the October 1999 meeting were approved.
- October 1999 OMSAP/PIAC/IAAC membership lists
- May 17, 1999 draft IAAC meeting summary
- OMSAP Charter
- MWRA's Food Web Model Scope of Work
- Revised IAAC Mission
Summary prepared by C. Coniaris. Post-meeting comments are included in [brackets].