NPDES Permits in New England
Outfall Monitoring Science Advisory Panel (OMSAP) Meeting
Friday, December 18, 1998, 11:00am to 3:00pm
Members Present: Andy Solow, WHOI (chair); Robert Beardsley, WHOI; Robert Chen, UMB; Robert Kenney, URI; Scott Nixon, URI; Judy Pederson, MIT/Sea Grant; Bill Robinson, UMB; and Jim Shine, Harvard School of Public Health.
Observers: Peg Brady, MCZM; Leigh Bridges, MADMF; Cathy Coniaris, OMSAP Assistant; Patty Daley, Cape Cod Commission; Mike Delaney, MWRA; Jim Fitzpatrick, HydroQual; Maury Hall, MWRA; Carlton Hunt, Battelle Ocean Sciences; Russell Isaac, MADEP; Ken Keay, MWRA; Christian Krahforst, MCZM; Kristyn Lemieux, ENSR; Matt Liebman, EPA; Steve Lipman, MADEP; Ron Manfredonia, EPA; Robert Michener, BU; Mike Mickelson, MWRA; Joseph Montoya, Georgia Tech; Jim F. O'Connell, Cape Cod Commission; Arleen O'Donnell, MADEP; Cornelia Potter, MWRA Advisory Board; Susan Redlich, WAC; Virginia Renick, MWRA; Andrea Rex, MWRA; Larry Schafer, retired; Jack Schwartz, MADMF; Rich Signell, USGS; Ted Smayda, URI; Dave Taylor, MWRA; Heather Trulli, Battelle Ocean Sciences; and Salvatore Testaverde, NMFS.
Summary prepared by C. Coniaris. Post-meeting comments are included in [brackets].
SUMMARY OF ACTION ITEMS
- C. Coniaris is drafting a protocol which will describe the procedures of OMSAP, PIAC, and IAAC. [A draft will be sent to OMSAP, PIAC, IAAC, EPA, MADEP, and other interested parties for comment.]
- OMSAP members will draft a statement describing why they approve of the Food Web Model Scope of Work outlined by MWRA and why they believe that the development of a food web model would not be feasible at this time due to the present gaps in knowledge of certain processes in Massachusetts and Cape Cod Bays. This statement paper will be distributed before the next meeting, discussed, and voted upon at the March OMSAP meeting. [Update: the OMSAP have postponed completion of their statement paper until after additional discussion and presentation of the current MWRA phytoplankton/zooplankton monitoring program at the March 22, 1999 OMSAP meeting.]
- OMSAP agreed to review the results of the nitrogen-15 stable isotope sampling study when it is completed.
SUMMARY OF MEETING
Members were asked to meet after the meeting to discuss potential new membership. C. Coniaris is drafting a protocol that will describe the procedures of OMSAP, IAAC, and PIAC.
APPROVAL OF THE OCTOBER 1998 OMSAP MINUTES
B. Beardsley requested his statement about N15 be deleted since he did not actually make the comment. Members approved the minutes as amended.
M. Mickelson gave brief monitoring update. Battelle has completed all of the 1998 sampling. A right whale and two humpbacks were observed feeding during the December water quality survey. C. Hunt stated that fewer stations were sampled in the nearfield during the December survey so that more samples could be collected along the Cape Cod Bay boundary.
M. Mickelson then showed model results which included a transect from the Boston Harbor to Stellwagen Bank and Provincetown, as requested at the October OMSAP meeting [results can be seen at http://www.mwra.state.ma.us/harbor/enquad/fwm.ppt ]. J. Shine asked why the areas under the curves are not the same. R. Signell replied that the areas are not identical (isotropic), however integration shows that they are very similar.
PUBLIC INTEREST ADVISORY COMMITTEE UPDATE
C. Coniaris gave a brief summary of the December 15 PIAC meeting [summary available]. PIAC advises OMSAP on important public concerns so that they are aware of those issues as they review scientific information. PIAC is also responsible for bringing OMSAP's decisions back to their constituencies. At the PIAC meeting, everyone introduced themselves and described their respective organizations. The group then spent most of the meeting discussing PIAC's roles and how it will function. The group agreed that it will attempt to work to consensus but since there are such varying interests in the group, any opposing opinions will be reflected in the minutes. The citizens' issues will first be discussed at PIAC and then brought to OMSAP. The group agreed to meet 4-6 times a year, about a month before OMSAP meets so that there is enough time to discuss issues and present them to the OMSAP. PIAC also agreed to meet if an important issue arises. PIAC agreed that their first item of business is to compile a list of issues to address and place them on a time line. PIAC agreed that they will review the OMSAP minutes as well as the other materials made available to the OMSAP so that they can discuss any issues that they feel are important. Cate Doherty will report to OMSAP on PIAC proceedings. Several PIAC members agreed to try to attend OMSAP meetings so that they can report back to PIAC. PIAC will have email discussions, as needed, as a way of communicating, and they requested that MWRA notify them whenever they are close to exceeding a threshold. PIAC also agreed that flexibility should be maintained as the functions of all three groups are determined. PIAC only had time to briefly discuss the food web model scope of work, however, they did not forward any recommendations to the OMSAP.
S. Redlich (PIAC member) added that PIAC members were also very interested in the opportunity that PIAC afforded in terms of exchanging information among the groups. In addition, PIAC is a conduit for a larger audience - the public - and needs to be aware of what questions and issues are out there. She also added that some of the members need to understand the role of the OMSAP better since they are new to this outfall monitoring process. By attending OMSAP meetings, PIAC members can get a better understanding of how things function. P. Daley (PIAC member), who also attended the meeting, approved of the summary.
INTER-AGENCY ADVISORY COMMITTEE UPDATE
S. Testaverde, interim IAAC chair, gave a brief update. The IAAC has a tentative agenda and will set up a meeting in February [Wednesday, February 24, 1999 1:00-3:30 PM at EPA Boston, summary available]. The IAAC will explore in depth what its charge/mission is. C. Coniaris listed IAAC membership and stated that IAAC is charged with advising OMSAP on the varying agency perspectives on scientific issues.
DRAFT FOOD WEB MODEL SCOPE OF WORK (FWMSOW)
M. Delaney described MWRA's perspective on this issue. MWRA has spent approximately 20 million dollars since 1991 on outfall monitoring, modeling, and reports. MWRA is spending about 3 million a year on the current monitoring. Joe Favaloro [director, MWRA Advisory Board] had asked him why MWRA is working on the FWMSOW since the permit is still a draft. M. Delaney had responded that MWRA expects that the final permit will include the FWMSOW and MWRA would like guidance from the OMSAP on the approach which they are considering. M. Delaney then read from Doug MacDonald's [executive director, MWRA] May 4, 1998 comments on the draft permit to EPA/MADEP: "MWRA should not be asked to do things more appropriately undertaken by other agencies. We are particularly concerned about the scope and extent of the reporting requirements in this permit." MWRA strongly feels that the science should not be allowed to fall behind by trying to attempt something which is not feasible. MWRA would like OMSAP's input on the approach presented today.
C. Hunt then provided background information, presented the approach mentioned by M. Delaney, presented results of a nutrient sensitivity analysis (i.e. response due to outfall) using the Bays Eutrophication Model, further defined what the FWM issues/focus are, and requested guidance from the OMSAP on the next steps. [The complete presentation is posted at: http://www.mwra.state.ma.us/harbor/enquad/fwm.ppt ]. A scope of work defines necessary work but is not a work plan by which one does the work. There are issues of uncertainty which need to be addressed in terms of developing a defensible model: (1) feasibility of developing a predictive model; (2) appropriate goal and approach; (3) level of nutrient change in the receiving waters required to impart a change in the prey of right whales; (4) a modeling exercise of this type is open-ended; (5) and factors other than the outfall that may be affecting the right whale and/or its prey in the Bay.
The MWRA is focusing on the development process of a food web model by using a flow diagram with several levels. The first level is the review of any previous assessments for conclusions and assumptions, update that and validate those assumptions with the seven years of baseline data, conceptualize a FWM (conducted by Kelly, et al. 1998), and perform a sensitivity analysis of MWRA loading using the Bays Eutrophication Model (BEM). C. Hunt showed some of these results later in the presentation.
Once this information is gathered, the following question will be asked: "will the environmental conditions be worse than predicted?" New information will help answer this. If the answer is no, then monitoring should be continued and the same question will be revisited annually. If the answer is uncertain, then there may be other research which could be conducted to address specific issues and questions in terms of uncertainty. If the answer is yes, then MWRA would have to go to the next level: "is such a change likely to harm whales?" Again, there would be a similar cycle. C. Hunt went on to explain the rest of the flow chart.
C. Hunt then described the conclusions of the review of assessments. EPA's 1988 Supplemental Environmental Impact Statement (SEIS) and EPA's 1993 Biological Assessment determined that there would be some impacts to the environment by the effluent but that they would be localized. The 1993 NOAA Biological Opinion (BO) stated that there will be "no jeopardy" to the existence of right whales. The BO examined three pathways: (1) increased nutrient loading to the Bays due to outfall relocation from Boston Harbor into Massachusetts Bay; (2) increased nutrient dispersal/transport to farfield areas of the Bays due to direct discharge of effluent at the proposed site in Massachusetts Bay; and (3) nearfield generated impacts and the outfall as a nuisance attraction for endangered species and/or prey of endangered species. C. Hunt presented information which supported this conclusion. "No jeopardy" means that there may be some effects on the environment but that there is no jeopardy to endangered species. Recent data has indicated that the assumptions in these assessments were conservative.
The effluent will be cleaner than predicted in the assessments since the assessments considered primary and not secondary treated effluent. Higher loads were used in the impact assessments compared to November 1998 MWRA data. Some of the predictions state that there may be lower phytoplankton and biomass in the area of the outfall which may mean that there will be less zooplankton for the whales to feed on. There are also major forcing functions on the total whale food web that are external and will likely override local effects.
Since the original assessments, R. Signell has developed a dilution transport model (1996) which has become more sophisticated over time with the addition of stratification and better advective terms. MWRA has also examined a number of other reports and data analyses. C. Hunt discussed the dilution transport model, nutrient loading, and recent sensitivity analyses.
C. Hunt then described a mass balance based on the 1992 BEM model results. Using the 1992 calibrated BEM model, MWRA examined the flux of nutrients across all of the boundaries, including MWRA, atmosphere, non-point, other wastewater treatment plants, and riverine inputs. He showed both dissolved inorganic (DIN) and organic nitrogen (ORGN) inputs. MWRA also examined the import at the boundary by Cape Ann and the export that exits by Cape Cod. The total input from the MWRA effluent is about 3% of the total nitrogen entering into the Mass Bay system. 5% is from non-MWRA sources and 92% from the boundary. R. Signell pointed out that the Cape Cod Commission information briefing states that MWRA is the largest point source in the system compared to the other sources. This is not inconsistent with the data which have been presented, but one must realize that there is already a large nutrient pool out there.
C. Hunt then presented recent model nutrient loading sensitivity analyses. MWRA put together six scenarios. "COL" is the current outfall location. "0x" is perfect nutrient removal from Deer Island, but not other treatment plants. "1x" is SEIS level predicted input with primary treated effluent. "2x" is the doubled nutrient concentrations using the same water flow. The responses of DIN, TIN, total nitrogen, chlorophyll and oxygen were modeled in the system, both at the current outfall and future outfall locations. All runs used the same coefficients and the same modeling format using primary treated effluent. M. Liebman suggested to repeat this exercise using current data in order to tie together the 1988 predictions and the current predictions. K. Keay replied that MWRA plans to work with HydroQual to produce additional model runs with more baseline data.
C. Hunt then showed the results of the sensitivity analysis for nitrogen, silica, phosphorus, carbon, and chlorophyll in the effluent for April 18, which is at the end of the winter/spring bloom and the period of most concern to the whales. T. Smayda asked if the model includes uptake, or just dilution and dispersion. J. Fitzpatrick stated that it includes phytoplankton uptake, remineralization of organic/detrital matter, and a first-order reaction rate for the effect of zooplankton predation. C. Hunt added that a full benthic cycle is also included. There was a brief discussion on model parameters. C. Hunt then presented the bottom dissolved oxygen model results for October 20. This day was chosen since it is the time of year when bottom dissolved oxygen levels are the lowest. Values ranged from 5 to 9 mg/l.
T. Smayda asked if vertical profiles of nutrients at depth were produced for this exercise so that thin layers, dispersion, entrapment of nutrients, subsurface plumes, and vertical distribution could be seen. C. Hunt stated that a high-resolution profile has been done which includes transmissometry, DO, salinity, chlorophyll, and temperature. T. Smayda asked if BEM will not be able to model nutrient build-up downstream at depth. J. Fitzpatrick replied that the concentration changes seen in the model results in Cape Cod reflect this. Phytoplankton biomass and productivity were examined during the critical summer period in the nearfield since there will be an introduction of increased nutrient concentrations in the immediate vicinity of the future outfall. Increases in primary production were seen, primarily due to the fact that there are nutrients at depth with some light penetration. Changes in productivity were not seen in Cape Cod Bay. Some of the bottom nutrients would gradually bleed up into the surface in shallower sections of Cape Cod Bay. T. Smayda added that they could also be bioconvected. R. Signell pointed out that since the plume is trapped in the lower layer during the summer, it is more likely to follow the topography and travel parallel to the coast. When there is less stratification, the plume will tend to wander out into the bay. C. Hunt added that the outfall monitoring program will include plume tracking during four different times of the year in order to define dilution and other processes. The plume tracking will include high resolution measurements using a towyo [apparatus which is towed up and down off the side of a research vessel on which various instruments can be attached].
C. Hunt believes that there is a lack of fundamental knowledge of many key processes. The development of a rigorous, predictive food web model can not be developed without better understanding of fundamental ecological processes, prey-whale energetics, and whale foraging decision making. There are a lot of relevant fundamental research areas which have been identified which would give us a better understanding of the effects humans have on the endangered right whale. The area is "ripe" for fundamental/basic research and selected modeling efforts linked to research could prove useful when looking at the local Mass Bay effect on endangered species. He pointed out that MWRA's monitoring program is the most comprehensive marine ecological outfall monitoring program in the world with almost every compartment in the system examined. The question is, where does MWRA responsibility end and others agencies' responsibilities begin?
J. Shine asked how the model addresses transport across the pycnocline. J. Fitzpatrick replied that given the diffuser structure, most nutrients will remain trapped below the pycnocline during the summer months, and essentially will not break through. A relatively small quantity of nutrients do diffuse through that layer, with local impacts on the primary productivity in the nearfield, and there may be a small localized increase in phytoplankton biomass at depth.
B. Chen asked how good the model is at predicting chlorophyll (i.e. how do predicted vs. observed compare). J. Fitzpatrick gave the example that models do relatively well in predicting the climate but do not do a very good job at predicting the weather. The model picks up some of the major features seen in the Mass and Cape Cod Bay system such as the fact that blooms begin earlier in Cape Cod Bay and with a higher magnitude. The blooms pulse and then decrease to less than one ug/l for most of the rest of the summer. Boston Harbor usually has a 2-3-fold higher chlorophyll concentration with respect to Mass Bay. The model predicts the nutrient dynamics correct in the sense that silica limitation is observed first in Cape Cod Bay and is followed by nitrogen limitation. It approximately gets correct the N:P ratios in terms of resolving inorganic and organic phosphorus. However, the model does not discern unique blooms. It will not predict Phaeocystis because no one understands enough of the algal physiology to be able to build that into a model. It also does not necessarily do well with all blooms of unique species that come and go over a week or couple of week basis. But it usually does well with average seasonal conditions.
R. Signell pointed out that the box calculation for the boundary might be a little misleading because it considers the whole source. What is relevant is the signal of the local outfall above the background. The term "source" from the offshore boundary would only be the current background. J. Fitzpatrick added that it is important to note that the system, even in the absence of MWRA, would have an input of nutrients and would support some level of primary productivity. C. Hunt added that this analysis looked at the inputs and some response factor in the Bays. There is a visible response to the additional nutrients in the effluent, however, the detectability of response in Cape Cod Bay is relatively low.
Request for Scope of Work -- Concerns
T. Smayda pointed out that Mass and Cape Cod Bays are nitrogen-sensitive, nutrient-enhanced, and regionally coherent. He is concerned that MWRA has focused on the dose-yield relationship between nutrients and phytoplankton and not enough on the ecological status, i.e. the relationship between nutrient loading and trophic response. He would like to see a monitoring program implemented which would examine the community response and be able to model in a helpful manner. He feels that while there has been a lot of data collection, there has not been enough hypothesis formulation and hypothesis-testing. He also believes that there is an intrinsic bias in much of the data collection (e.g. phytoplankton) with the habitat-status or dose-yield approach. The hypothesis which should be the basis of the model: "In nutrient-enhanced systems, associated changes in phytoplankton blooms, community structure and species succession are not a response to nutrient modification, but to changes in grazing pressure, i.e., failure of normal grazing processes". Two levels of hypotheses should be regarded as an intrinsic part of the model and scope of model. The first level relates to abundance and composition of zooplankton in Mass and Cape Cod Bays. The second level is patchiness. The hypothesis related to whales states that there is or has been a significant change in the extent of copepod patches acceptable to right whales. The focus should be on grazing and secondarily on nutrients.
He believes that there is a very low level of frequency of sampling in Cape Cod Bay both temporally and regionally. He then showed seasonal data from Narragansett Bay which shows that the winter-spring bloom can occur anywhere from November to February. This time variability must be considered since this area is at a sensitive biogeographical jump from boreal and temporal/boreal. Because of this, sampling needs to be as quantitative as possible, not only in terms of procedure but in modeling because this variability. If there is ever a catastrophic die-off, the cause should be discerned -- MWRA or other reasons. The scope of a model is necessary and should be able to quantify as closely as possible what is occurring in order to be able to make quantitative and cost-effective decisions (e.g. retrofit Deer Island, if necessary).
T. Smayda believes that it is reasonable to request that a model of suitable scope be incorporated which would then allow for quantification. This will not be perfect, but it is defensible. Perhaps the new outfall will not impact the right whale. But a right whale based model will also address to engineering, public health, and red tide issues. It has the potential of possibly discerning particular factors involved. He encouraged that the model have sufficient scope to allow for these kinds of decisions and that the monitoring program also be expanded.
B. Robinson asked if T. Smayda felt that there was enough baseline data being collected. T. Smayda replied that there is adequate baseline data for particular times but not a lot of information is collected to learn about certain important things, for example, examining the microbial loop. He believes that we should use baseline conditions (and not "pristine" conditions) as our "start" position and to somehow use that as an index of change. B. Robinson believes that the biggest issue is potential change in community structure of phytoplankton/zooplankton. He asked if there is enough baseline data to really understand what the natural variability is over a 10-20 year period for the new outfall site. T. Smayda replied that the natural variability is not known. There is significant information available but he believes that the OMP sampling frequency and distribution is inadequate.
J. Shine asked if there is a good understanding of variability on a basic science level, not just in Massachusetts Bay. T. Smayda replied that this is currently under considerable debate. What is known is that blooms last longer and bloom species tend to be less diverse, and eventually become monospecific. J. Shine asked if T. Smayda expects MWRA to take on these basic research questions and incorporate them into a model. T. Smayda replied that monitoring only allows one to be reflexive when something has happened, but does not allow one to be reactive. To get around that kind of a problem, there needs to be process-oriented modeling and monitoring to examine key concerns.
B. Beardsley asked for some examples of what should be measured. T. Smayda suggested zooplankton grazing and phytoplankton uptake of nutrients over time. A. Solow requested that T. Smayda provide a specific list of suggestions about how the monitoring program could perhaps be modified or changed. S. Nixon does not see how OMSAP can endorse a scope for a project which may or may not be desirable. A. Solow suggested that one way is to have this scope of work available and if in the future, the question of implementation arises, a decision will have to be made as to whether that work should be done. B. Robinson asked about phytoplankton/zooplankton monitoring. M. Mickelson replied that MWRA has been monitoring and enumerating phytoplankton/zooplankton species since 1992. The program will continue and any cutbacks in the program will occur only with the approval of OMSAP. B. Robinson would like to see some of the results. M. Mickelson stated that MWRA would be glad to revisit this. [Update: the MWRA will present an overview of the phytoplankton/zooplankton monitoring at the March 22, 1999 OMSAP meeting.] MWRA has drafted a zooplankton retrospective, phytoplankton issues review, and other reports which specifically deal with these aspects. There are also seven years of baseline data. C. Hunt briefly described the phytoplankton/zooplankton monitoring program. M. Mickelson showed a map of zooplankton/phytoplankton stations at which biomass and species are measured.
B. Beardsley asked T. Smayda if he could elaborate more on the time period in which he does not expect much change. T. Smayda replied that the timing is driven by the right whales and summer red tide outbreaks. He briefly described the pre- and post-discharge sampling scheme recommended by the Barnstable Science Advisory Panel. He feels that there is no sense doing any kind of modeling if the right monitoring is not being done. B. Robinson does not think that the second row in the flow chart "will environmental issues be worse than predicted?" is useful. When looking at the phytoplankton/zooplankton community structure, one can not determine "yes", "no", or "uncertain". M. Delaney responded that this is based on examining changes since 1993, when the original determinations were made.
B. Chen pointed out that there is a lot of unknown between nutrient/phytoplankton dynamics and right whales dynamics and there is an ongoing need for research studies. He believes that at the present time, one can not show the potential effects of MWRA on right whales. The debate now is whether MWRA should set up a model which incorporates new findings, however, the model may never become useful. B. Kenney believes that the nature of the linkages and how to quantify them is unknown at the present time. No advances will be made by forcing something to happen before the data are available.
A. Solow believes that there are two ways to approach this. One is to recommend that the FWMSOW requirement be changed in the permit. The second would be to approve the scope of work, even if it involves a model that OMSAP agrees will not come to fruition (negative reaction from members). J. Pederson feels that it is risky because if the scope of work is inclusive and becomes a part of the response to the permit, then it becomes law. S. Nixon agreed with T. Smayda in that there is no point to have a model if there is not adequate data to verify it with. The state of the art does not allow for the construction of a credible, useful and dependable model. He stated that it would be wonderful if we had such a model but we do not and there seems to be no prospect of having one in the near term or median term future. Therefore to require MWRA to go forward and attempt to develop this would be more misleading than useful.
B. Kenney believes that this presentation satisfies the scope of work permit requirement. J. Shine pointed out that it will be impossible to reach "model development" on the flow chart. J. Pederson is concerned about what the responsibility of MWRA is verses others who support research. Developing a food web model is a research, not a monitoring, question. The Gulf of Maine Regional Marine Research Program discussed the issue of zooplankton grazing and determined that there is not a lot known, existing data are fairly inconsistent from area to area, and it is not clear that funding one more study will add to that. She suggested to at least do a literature search to examine what is known and not known. B. Kenney pointed out that OMSAP believes that a model would be desirable. However, a model is not feasible at this point. A. Solow added that it seems that it is not just feasible because of a lack of data, but models of nature are complicated. Even if there were much better measurements of many of the vital rates, it still may not be enough to build a predictive model. B. Robinson suggested that OMSAP accept this as a scope of work but that implementation is not possible at this time. J. Shine suggested asking MWRA to outline what is known and not known about the food web. B. Chen suggested leaving "a door open" so that as new knowledge becomes available, MWRA can add to the monitoring program in order to augment the understanding of the system. He would like to allow for potential model development in the future.
J. Pederson and B. Robinson pointed out that there are different types of models, both qualitative and quantitative. B. Kenney added that the point of a model is to predict where, when, and how many right whales will be found, for example, if a red tide bloom occurs. Crucial information, such as what causes those red tides or what forms the zooplankton patches the right whales feed on is not well understood.
M. Mickelson pointed out that any time the OMSAP requests that MWRA look into new information about modeling, it will be done. A permit requirement should not be required for that. This permit requirement sounds like MWRA has to take full responsibility for the departing of right whales. MWRA has countered with the following approach: first show MWRA has changed the environment in some significant way and then show that the change would harm the whales before considering whether there is enough information for a food web model. P. Daley believes that the monitoring program should spend more effort in examining the variability in the system. M. Delaney argued that MWRA does look for variability and will continue to do so. If there is a change, MWRA will detect it. The previous Task Force debated the form of the monitoring program, and MWRA is always receptive to improvements to the program. K. Lemieux thinks that MWRA has been very supportive. ENSR has prepared for MWRA several special issues reports and are currently preparing one on Phaeocystis which examines naturally occurring correlations and environmental variables. ENSR has also worked on a retrospective which looks at variability among other available data sets in order to augment the baseline data and get a handle on that spatial and temporal variability.
J. Pederson asked if one of the regulatory agencies could comment on this. M. Liebman stated that the permit will not be ready until after December 31, 1998, but the December 31st deadline was not going to change [update: the deadline has been extended]. The draft permit did contain a requirement that MWRA submit a scope of a food web model. This scope of work is a just plan and not a program and EPA/MADEP will rely on OMSAP's comments. A. O'Donnell added that EPA/MADEP would like feedback from the OMSAP on the scope of work and whether it should be implemented. G. Renick pointed out that it is really up to EPA/MADEP to show that by issuing the permit that no harm will result.
A. Solow suggested a motion that OMSAP accept the scope of work, that that a FWM is desirable but that OMSAP does not favor implementation at this time because the scientific knowledge needed is not available at the present time. J. Shine added that there should be hypothesis-driven data collection. B. Beardsley asked if OMSAP will summarize details of any motion in a statement paper and if there will be extended commentary as a way of having agreement in principle. A. O'Donnell suggested that OMSAP vote to draft a motion to be included in the minutes and then formally vote on the motion at the next OMSAP meeting. OMSAP approved that statement as a motion and voted in favor of it unanimously [S. Nixon had departed before the vote]. J. Shine pointed out that the draft scope of work includes continued monitoring and annual re-evaluation. A. Solow nominated J. Pederson to draft the statement but she nominated B. Kenney. He accepted. Members agreed to review drafts of the statement via email. [Update: the OMSAP have postponed completion of their statement paper until after additional discussion and presentation of the current MWRA phytoplankton/zooplankton monitoring program at the March 22, 1999 OMSAP meeting.]
OMSAP MEETING FORMAT
A. Solow stated that the OMSAP needs to be able to have free and open discussions of scientific issues. OMSAP meetings are open to the public and this may constrain the willingness or ability of the Panel to talk openly. C. Coniaris is working on the OMSAP protocol and one proposal is that it include that time be set aside at each meeting during which the Panel have their own discussion after which, audience members will be allowed to ask questions. The OMSAP will need this kind of quality time in order to be able to get things done in an effective way. L. Schafer and C. Krahforst believe that open meetings can work, as long as there is tight control in the participation in the audience. J. O'Connell suggested to perhaps have an additional meeting if there was not enough time to absorb the information, discuss, and develop opinions.
NITROGEN ISOTOPE RATIOS AS A TRACER FOR SEWAGE
INPUTS TO THE COASTAL ZONE
J. Montoya summarized the method for using isotopes of nitrogen as an effluent tracer. The December 18, 1998 information briefing describes this method. J. Montoya believes that this gives an actual tracer for the nitrogen into the biota and could prove whether nitrogen from the outfall is having any impact. This approach can be useful not just in quantifying the local impact of sewage nitrogen on the biota but actually setting a biogeochemical index limit on nutrients.
Members then asked questions about the method. B. Robinson asked about background concentrations and other inputs to Mass Bay. J. Montoya replied that the sampling strategy should take these concerns into account. Though smaller sources may not be differentiated, the signature in the vicinity of the outfall will be strong. B. Chen asked about the effects of sediment denitrification. J. Montoya replied that sediment denitrification has little net discrimination because it is usually coupled with nitrification making the net effect about zero. C. Hunt pointed out that since this traces all particles, it includes the bacterial signature which creates a lot more variability. Data presented are based on the current discharge location and thus the signature should shrink in area with the new outfall due to greater dilution.
A. Solow asked why this should be monitored on a regular basis, and not just as a "special study". J. Montoya replied that MWRA should be interested in being able to point to a set of data which shows that there is no biogeochemical evidence that the nitrogen from the outfall is having any impact on the biota. He does not know another way to follow the nitrogen into the biota.
M. Liebman asked about variability. J. Montoya replied that one would have the same variability as measured in other biological processes. B. Beardsley can see how this could be useful in the nearfield but asked how one would differentiate "spikes" in Cape Cod Bay due to variability. J. Montoya replied that there will always be variability in synoptic sampling. The best job one could do is to collect good data in order to be able to delineate the spatial extent of this signature. Even though there is this variation in the source, the dominant signal that is expected is a large isotopic effluent signature. J. Shine pointed out that one would not want to get a false positive with a signal from another source. J. Montoya agreed and stated that other sources and variation would also have to be studied.
A. Solow asked if this could be used as part of a food web model. J. Montoya thinks that adding zooplankton N15 measurements could add a quantitative geochemical component to a food web model. D. Taylor added that the N15 method has been used with particulate material but there is now a mechanism to measure it using ammonium and nitrate, which have a larger wastewater background signal. Nikki Sheats' work suggests that secondary treated effluent will have an even larger signal. However, there are some negative aspects to this method as well. One is the sensitivity of the method relative to the increased dilution in Mass Bay and thus detectability. Another is the separation from alternative sources, the Merrimack River, groundwater from Cape Cod Bay, as well as other factors. There is very little DIN N15 baseline data available for both the effluent and Mass Bay and not enough time to collect very much before the outfall goes on-line. There will be cooperation in collecting some baseline data. MWRA has agreed to supply the CCC with samples from the secondary treatment plant (one per month December to July) and Battelle has offered to supply excess water from their farfield surveys for analysis. B. Michener's lab at BU has offered to analyze the samples. A. Solow asked if any samples will be collected "upstream" in order to measure water entering Mass Bay. K. Keay replied yes. M. Mickelson posted the stations locations.
J. O'Connell asked OMSAP if they believe this method can add significant information. He asked that OMSAP review the N15 report when it is completed. OMSAP agreed to review the report. C. Hunt suggested that source terms such as Cape Cod Bay groundwater intrusion be examined. OMSAP members felt that this method could potentially prove to be a valuable monitoring tool. They welcomed future presentations on this topic as more information arises.