### 1 Comments on the National Pollutant Discharge El imination System Draft Permit for the Indian River Generating Station

April 4, 2008

Chris Bason, Science Coordinator, Delaware Center for the Inland Bays

The Delaware Inland Bays have historically pr ovided productive spawning grounds, nursery areas, and adult habitat for a variety of commercially and recrea tionally important shellfish and finfish. Over the past century, cumulative impacts have severely degr aded fish and shellfish habitat and thus the recreational and economic value of the fishery of the Inland Bays. These impacts include conversion of estuarine habitat to other landuses, chronic eutrophi cation and associated habitat degradation, and a reduction in lower-salinity habitats due to the stab ilization of the Indian River Inlet. Another lessdiscussed but long-standing impact on the fishery of the Inland Bays is the Indian River Generating Station (IRGS). The IRGS is currently permitted to use once-through condenser cooling that withdraws water from Indian River and discharges heated water to Island Creek off Indian River. Data from two studies that were contracted by NRG (2001 & 2003) to assess the environmental impacts of the cooling water intake and discharge demonstrated that 1) the fish habitat value of Island Creek and portions of the adjacent Ware Cove is degraded by the IRGS therma l discharge and 2) the cool ing water intake annually kills the equivalent of millions of a dult fish and hundreds of thousands of adult blue crabs. This results in a) significant degradation of the Indian River a nd Bay and the Rehoboth Bay as nursery habitat, b) significant contribution to the degradation of the econo mically important Inland Bays recreational fishery, and c) alteration of the entire food web of the Inla nd Bays. The conclusion of these studies was, however, that the IRGS had no adverse environmental impacts. Generally, these conclusions were made by using inappropriately large scales as the frame of refere nce for which to determine an impact to local ecosystems. For example, the hundreds of thousands of adult blue crabs killed annually by the plant were related to the entire blue crab population of Ma ryland and Delaware and thus characterized as insignificant. The federal Clean Water Act and the State of Delaware Water Quality Standards require that best available technologies be applied to po wer plants to minimize any adverse environmental impacts. A closed-cycle water system with a cooling tower in this case appears to be the best available technology because a cooling tower was constructe d on IRGS unit 4 which was permitted under these federal requirements. The above studies were requi red of NRG by DNREC approximately 15 years ago to provide sufficient information to determine if an appreciable environmental impact to Island Creek and the Inland Bays fishery from the IRGS was occurring. The draft permit requires new studies to determine if best available technology is needed. Now requiri ng additional studies to make this determination again based on future scenarios of IRGS operation appear to be in conflict with the DNREC’s previous requests for the above referenced studies that, once completed, demonstrated appreciable environmental impact yet resulted in no requirement for applying best availa ble technology. It is recommended that DNREC not issue the current draft permit and promptly develop a new draft permit with the requirement that the IRGS expeditiously employ best available technology to mi nimize all fishery and habitat impacts for its power generating unit number three, if it intends to maintain this unit under this requirement. It is recommended that, as a condition of the permit, estuarine ecosystem restoration and enhancements projects to be formulated and agreed upon by the Center, DNREC, a nd NRG, be implemented in the Inland Bays by NRG in coordination with the above parties as m itigation for impacts from power generating units number one and two until their shutdown per the 2 007 consent order between NRG and DNREC. The following is a brief review of the informa tion used to formulate these recommendations.

Background The IRGS has three coal-fired steam electric generati ng units that withdraw cooling water via an intake canal from the Indian River at a maximum rate of 411 million gallons per day (mgd). For purposes of comparison, this is approximately 21 times the average flow of the freshwater Indian River. Each year millions of fish and hundreds of thousands of crabs are killed through entrainment and impingement

### 2 associated with the plants’ cooling water intake structures. Entrainment is when small aquatic organisms are (fish eggs & larvae) are drawn through the plan t’s cooling water intake screen, pass through the condensors and exit. They can be killed or injured such that they later die as an indirect result. Impingement is when organisms that are too large to be entrained and that can not escape intake are caught on the intake screen. They can die directly or indirectly from wounds. Environmental impacts from the plant also result from the heated cooling water that is di scharged via a canal into the upper reaches of Island Creek. Island Creek is an approximately 2 miles long tidal tributary of the Indian River Bay that comprises approximately 150 acres of estuarine habitat. The IRGS has had a long an unusual permitting history. A timeline of the major events associated with the permitting of the facility is presented as an attachment. It is important to note that IRGS power generating unit 1 and unit 2 are scheduled to go offline in 2011 and 2010 per a consent decree between DNREC and NRG.

Regulatory and Permitting Matters The Delaware Inland Bays are Waters of Exceptional Recreational or Ecological Significance (ERES). Under the State of Delaware Water Quality Standards the Department of Natural Resources and Environmental Control shall assure that 1) there sh all be achieved the highest statutory and regulatory requirements for all new and existing point sources 2) in order to be permitted, a discharge must be the least environmentally damaging practicable alternative, and 3) a permit shall not be issued or reissued for an existing source unless the applicant demonstrat es a utilization of all economically feasible and reasonably available waste minimization practices and technologies, and the lack of feasible alternative production processes and disposal optio ns. Potential water quality impairment associated with a thermal discharge must be consistent with Section 316 of the Federal Water Pollution Control Act (Clean Water Act). Section 316(a) allows a variance from meeting effluent thermal limits if no appreciable harm has resulted from the normal component of the discharge. Section 316(b) requires that a point source shall require that the location, design, construction, and cap acity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact. NRG contracted two studies completed by Entrix in 2001 and 2003 that suggested no adverse environmental impacts from the thermal discharge and intake. NRG thus requested a varian ce from the 316(a) and (b) requirements. Currently, it appears that no official federal guidelines exist for determining an adverse e nvironmental impact that would require best available technology. In this case, best available technology appears to be a closed cycle cooling water system with a cooling tower. Individual states must now use Best Professional Judgment to determine an adverse e nvironmental impact that would require best available technology. Upper Indian River Bay including Island Creek is on th e 303d list of impaired wate rs and is impaired for bacteria, nutrients, DO, and temperature. The Indi an River/Bay also has a Total Maximum Load for Temperature. DNREC, and supposedly the EPA, have concluded that no appreciable harm to the aquatic

environment has occurred from the th ermal discharge but have not granted NRG’s request for a 316(a) variance. No 316(b) variance was issued either. Th e draft permit requires additional study that appears designed to determine if adverse environmental im pacts are occurring or will be occurring after the

scheduled shutdown of units 1 and 2.

Assessment of Environmental Impacts Impingement and Entrainment The 2003 316(b) was clearly designed to determine whether the IRGS was causing an adverse environmental impact (AEI) to the Indian River and Rehoboth Bay study area (page 1-3). AEI occurs when the ecological function of species are reduced su ch that populations decline, reductions in the optimum sustainable yield to fisheries results, or an unmitigable loss to the a quatic ecosystem occurs. The protection of a balanced indigenous community and long term sustainability of fish and blue crabs in the vicinity of the IRGS were two selected endpoi nts to determine an AEI. The endpoints were determined by modeling 1) the proportion of eggs, larv ae and juveniles lost due to entrainment relative to the number of eggs, larvae and juveniles present in th e study area (Empirical Transport Model (ETM)), 2) the number of adults lost due to the mortality of en trained eggs, larvae, and j uveniles (Equivalent Adult

### 3 Model (EAM)), and 3) the commercial and recreati onal value of foregone production for commercially and recreationally important RIS.

The study selected representative important species (RIS) based partly on their vulnerability to entrainment and impingement, recreational and econo mic importance. The species were bay anchovy, menhaden, spot, croaker, winter fl ounder, and blue crab. Anchovy a nd winter flounder spawn within the Inland Bays, their larvae use the Bays as nursery ground s, and adults of both species use the Bays almost year round. Menhaden, spot, and croaker generally spawn offshore and their juveniles migrate into the nursery grounds of the Bays. Full adults generally use the Bays for only part of the year. All the species play an integral role in the food web converting plan kton and benthic animal biomass into the biomass of the birds and fish that eat them. For example, the st udy states “the bay anchovy pl ay an integral role in the estuarine food web, representing an important link between plankton and [fish eating] fish and birds.... Serving as the primary forage fish for many avian and aquatic species, they have a long list of predators that includes herons, egrets, terns, weakfi sh, bluefish, striped bass, summer flounder, and blue crab... bay anchovy are one of the most ecologically important species within the Mid-Atlantic Region.”

The major results of the study are summarized in the tables below and are followed by definitions of the model results. On average, 2,397,5 33 equivalent adult individuals of the RIS are estimated to be killed each year by the plant. This equivalent number is modeled from the many times more fish eggs and subadult individuals that were killed. In addition, 300,000 a dult blue crabs are estimated to be killed each year. The magnitude of the impact of the plant intake on the bay anchovy population of the bays is particularly surprising. A bay anchovy spawned in the Inland Bays has an average 32% chance of being killed by the plant intake before it reaches non-en trainable size. The cumulative impact of the impingement and entrainment undoubtedly has a major effect on the food chain of the Bays by limiting the upwards flow of energy. For example, the study estimated that each year an additional 213 tons of menhaden and anchovy alone w ould be available to predators if not for the plant. Further, the numbers presented only include five of the over sixty species of fi sh found killed by the plant. It is reasonable to

believe the total number of individua l fish of all different life stages killed by the plant each year is multiple orders of magnitude higher than what is presented.

One important fish species that was not examined as an RIS was the weakfish. During the first year of study, weakfish were the fifth most abundant species killed by impingement of 60 species found impinged. They were also the 7 th and 4 th most entrained species in year 1 and year 2, with entrainment losses greater than all RIS except anchovy in year 2. The weakfish population is of particular concern because of its economic value, its recent population declines, and its local relative abundance. The weakfish was considered as an RIS in the earlier 316( a) study and it was unclear why it was not selected for the 316(b) study. The Department should consider the weakfish as another RIS when determining an

AEI.

### 4 Table 5-1. Output from the Empi rical Transport Model (ETM), Equi valent Adults Model (EAM), and

Equivalent Yield Model (EYM)

Total EYM (kg)2 Species ETM (% CMR) EAM (EQ1)1

Entrainment Impingement Total

Year 1

Bay anchovy 33 2,656,218 N/A N/A N/A

Atlantic menhaden 16 12,488 406 15,209 15,615

Spot 2 961 207 183 390

Atlantic croaker 5 518,910 32,793 5,593 38,386

Winter flounder 1 798,888 69,998 99 70,097

Year 2

Bay anchovy 31 636,272 N/A N/A N/A

Atlantic menhaden 20 110,618 3,592 142 3,734

Spot 2 0 255 0.1 255

Atlantic croaker 12 24,823 1,634 171 1,805

Winter flounder 7 35,887 3,408 0.9 3,409

Table 5-2. Results of the Production Forgone Model

Year 1 Production Foregone (kg) Year 2 Production Foregone (kg) Species Entrainment Impingement Entrainment Impingement

Bay anchovy 119,824 19 130,673 14.5

Atlantic menhaden 4,219 76,187 55,721 710

Empirical Transport Model, % Conditional Mortality Rate -- the percentage reduction in a species abundance attributable to the plant intake, or the percentage of the en trainable population that would be lost if entrainment were the sole source of mortality. Equivalent Adult Model – the estimate of the number of adults fish lost that would have lived if not for the plant. Equivalent Yield Model – the biomass that would have been harvested by commercial and recreational fisheries in the absence of entrainment and impingement. Calculated for coastal stocks. Production Foregone Model – the biomass of the prey species that would have been available to predators in the absence of entrainment and impingement.

The study concluded no AEI because its risk char acterization phase related the losses from impingement

and entrainment to the size of mid-Atlantic coastal fi sh stocks and the total fishery landings of Delaware and Maryland. This basis for determining an AEI to the Inland Bays is wholly inappropriate for the following reasons:

1. the study “was designed to collect the appropriate data to evaluate whether the current operations at the IRGS are likely to cause an AEI to the a quatic resources within the Indian River Estuary and Rehoboth Bay study area,” not to coastal stocks.

2. The endpoints selected to determine the likeli hood of an AEI were a) the protection of a Balanced Indigenous Community of fish and blue crab in the vicinity of the IRGS and b) the production of the long-term sustainability of fish and blue crab populations in the region influenced by the IRGS coo ling water intake structure

. By relating losses to coastal stocks in its risk char acterization phase, the study compromises its stated design to evaluate both the Inland Bays and the vicinity of the IRGS. Further, it is not reasonable to believe that one power plant in isolation could influe nce the sustainability of the entire mid-Atlantic RIS fishery, and so it is here interpreted that the regi on influenced corresponds to the Inland Bays. Using the approach of this study it is reasonable to conclude that no AEI to the RIS would occur even if the entire RIS population of the Bays were killed each year by the plant.

### 5 The study attempted to support their determination of an AEI on the local RIS populations by relating trends in the State of Delaware Inland Bays finf ish monitoring trawl data from 1986 through the study period to the plant. The study found no long term tre nds in fish populations and assumed no AEI. This is an unreasonable assumption because 1) there is no method to distinguish the affect of the power plant on populations from the myriad of interacting environm ental factors such as coastal stock fluctuations, habitat quality, and climate and 2) th e trawl data began years after the units came online and thus included no means to reference pre-existing conditions to de termine population change from the plant.

It appears that benchmark values suggested to determin e an AEI were referenced but then not used in the determination of AEI for this study. Conditional mo rtality rates, or the percentage reduction in thatspecies abundance attributable to the plant intake, of the RIS were compared to values of 10% for nonforage species and 15% for forage species. Th ese benchmark rates were borrowed from assessments made on the New Jersey Deep Water Generating Station on the Delaware River. It is not clear if these benchmarks are appropriately transferable between two greatly different estuaries. The study found conditional mortality rate of 33% for bay anchovy, over twice the recommended value for the Delaware River. An average rate of 18% was found for menhaden, again over the 15% value for forage species. It is unclear why these benchmarks were compared to study data but then apparently not used in the

determination of an AEI. The benchmarks alone suggest the occurrence of an AEI.

Based on the data presented in the 316(b) report it is clear to the author that the impingement and entrainment of the plant is having an adverse envi ronmental impact on the Inland Bays ecosystem. One would have a hard time trying to fi nd an independent professional fisheries scientist that would, in their best professional judgment, disagree. According to Stat e and Federal law, this requires the application of best available technologies to the IRGS.

316(a) The 316(a) study was briefly reviewed. The report assessed the affects of elevated water temperatures on eight representative important fish species: bay anchovy, menhaden, winter and summer flounder, croaker, spot, striped bass, and weakfish. The importa nt effects of the thermal discharge are the potential avoidance and subsequent reduction of available habitat and associated services experienced by the target species and other organisms inhabiting the study area. The study found that juvenile and adult target species were not required to permanently avoid major segments of the Indian River and lose the habitat services associated with these segments. The study conc luded no adverse effect, or no appreciable harm, on the fish and shellfish populations in the Indian River and Bay. The author agrees with these conclusions. However, the study concludes and clear ly demonstrates that, during the warmer months, the discharge has an adverse effect on Island Creek a nd sometimes the adjacent Ware Cove. Island Creek and Ware Cove is a large estuarine segment that provi des relatively important fish and crab habitat. Its lower salinity and position in the larger estuary is attractive to RIS such as bay anchovy, spot, and menhaden larvae, and young blue crabs. The potential mortality associated with sub-adult stages of fish and crabs and the avoidance of the area by sub-adult and adult fish is proportional to the size of the area affected which is large. The creek is about two mil es long and, including parts of the cove, is 150 acres of

estuarine habitat. Further, reductions in dissolved oxygen associated with the discharge were substantial (mean = 0.6 mg/l) even in Ware Cove. These reduc tions are in addition to cumulative effects of eutrophication on the widely fluctuating diel cycling dissolved oxygen concentrations of tidal tributaries to the Inland Bays. Island Creek is a significant tid al tributary of the Inland Bays and the determination of plant effects should focus on Island Creek and Ware Cove. The existing study is sufficient to make this determination and no new study is needed. It is clear that Island Creek and, during some time of the year, Ware Cove experiences appreciable harm fro m the discharge, and BAT should be applied.

On the Rationale for Requesting Further Study It was stated by representatives of DNREC that part of the rationale for issuing the current draft permit without requiring BAT was that AEI from impingement and entrainment were expected to decrease such

### 6 that the protection of a balanced indigenous co mmunity could result. However, no evidence was provided as to the likelihood that this would occur. What little evidence that can be drawn from the existing studies as is, appears to not support this because unit 3, the unit that will remain online for the near future, accounted for 72% of the total impi ngement losses whereas unit 1 accounted for only 28%. This makes sense because unit 3 is much larger than 1 and 2. Unit 2 was not directly sampled, so its

relative contribution to total losses is unknown.

Both entrainment and impingement sampling was accom panied by the volume of circulating water or flow rate based on the number of circulating water pumps in operation and/or the pumping rates. In fact, the Empirical Transport Model determined entrainment as a simple function of the plant’s measured intake flow rates. This suggests that the existing da ta could be used to determine the relationship between pumping rates and both impingement and entrainment usef ul for estimating the risk of an AEI after unit 1 and 2 have gone offline. Before issuing a permit requesting additional study, DNREC should attempt to use the existing data to estimate an AEI after units 1 and 2 have gone offline.

It is likely that similar modeling can be conducted with data from the 316(a) report to estimate if appreciable harm will occur to the fish assemblage of Island Creek after units 1 a nd 2 have gone offline. Given the legal status of the Inland Bays and th eir tributaries and their impaired condition from cumulative impacts, it is recommended that a highly pr ecautionary approach be used when estimating the potential for an AEI in the future.

Consideration of Cumulative Impacts Finally, there was no indication in the rationale for i ssuing the permit that the impacts of the plant were evaluated cumulatively with other impacts to the fish ery of the Inland Bays or with trends in regional populations. By not specifically considering cumulati ve impacts to the fishery, the justification for regulating individual impacts is weakened. DNREC s hould describe and consider the cumulative impacts to the fishery when determining the issu ance of this and other individual permits.

General Recommendations

It is recommended that DNREC not issue the current draft permit and promptly develop a new draft permit with the requirement that the IRGS expeditious ly employ best available technology to minimize all fishery and habitat impacts for its power generating unit number three, if it intends to maintain this unit under this requirement. It is also recommended th at, as a condition of the permit, estuarine ecosystem restoration and enhancements projects to be formulat ed and agreed upon by the Center, the Department, and NRG, be implemented in the Inland Bays by NRG in coordination with the above parties as mitigation for impacts from power generating units number one and two until their shutdown per the 2007

consent order between NRG and DNREC.

### 7 IRGS TIMELINE

DEC 1976 316(a) thermal discharge demonstration report prepared by Ecological Analysts Inc. for Delmarva Power & Light Co. was released.

??? 1978 316(b) entrainment and im pingement demonstration report prepared by Ecological Analysts Inc. for Delmarva Power & Light Co. was released.

???? 1980 IRGS Unit Four using closed cycle cooling comes online.

MAY 1983 NPDES Permit issued for the facility.

SEP 1988 Delaware NPDES Permit issued for the facility.

???? 1990 DNREC contracted Ver sar to review the 316(a) and (b) compliance of 12 Delaware facilities including IRGS. Versar concluded that th e studies from the 70s were outdated and the resulting data not representative of current conditions. Versar recommended DNREC conduct a formal review of the original 316(b) findings.

???? 1990 Delaware NPDES Pe rmit amended to change flow and loading limits, biomonitoring requirements, copper monitoring re quirements, and toxicity limits.

???? 1992 Based on Versar report DNREC dete rmined original 316 (b) findings outdated.

SEP 1992 Delaware NPDES Permit expired.

???? 1993 Versar, contracted by DNREC, recommends that DNREC require the then owners of IRGS to conduct updated 316(b) studies pr ior to the next permit renewal.

???? 1997 According to Peder Hansen, DNREC star ted working on the issue of impacts in earnest.

JAN 2001 316(a) (thermal discharge) ecological risk-based demonstration report prepared by Entrix for

Conectiv.

AUG 2003 316(b) (entrainment and impingement) ecological risk-based evaluation report prepared by

Entrix for Conectiv

JUL 2004 EPA Promulgates Requirements for Cooli ng Water Intake Structures at Phase II Existing Facilities (affects IRGS?). This requires est ablishes performance standards that are projected to reduce impingement mortality by 80 to 95 percent and, if applicable, entrainment by 60 to 90 percent. Details Best Available Technologies.

JUL 2004 DNREC IRGS visited to observe operations to develop permit limitations and conditions.

DEC 2004 EPA established a TMDL for temperature for the Indian River Bay

JAN 2007 EPA suspends the Cooling Water Intake Structure Regulations for existing large power plants. This suspension is in response to the 2nd Circuit Court of Appeals decision in Riverkeeper, Inc., v. EPA. State permitters are still required to establish section 316(b) requirements on a BPJ basis for existing facilities not subject to categorical section 316(b) regulations.

### 8 NOV 2007 DNREC releases public notice of NPDES permit

???? 2008 Effective date of the new permit

MAY 2010 NRG required to have shut down Unit 2

MAY 2011 NRG required to have shut down Unit 1

???? 2012 Expiration date of the new permit.