Document 1QGQDqJoJ6MJD6ZwbJpo1ZnrX

tPU> E. I. Du Po n t d e : Ne mo u r s S Co mp a n y INCORPORATED Ha s k e l l , La b o r a t o r y f o r To x ic o l o g y a md In d u s t r ia l Me d ic in e El k t o n Ro a d , Ne w a r k , De l a w a r e 19711 CENTRAL RESEARCH AND DEVELOPMENT DEPARTMENT M W. Kirkwood, DuPont, Canada April 18, 1984. T. M. TUSZYNSKI MAITLAND WORKS DU PONT CANADA LTD. MAITLAND, ONTARIO KOE IPO CANADA REVIEW OF THE REPORT ON THE BENTHIC SURVEY BY AMIK REGARDING LEAD POLLUTION PROBLEMS' The current standards for lead in the environment are: 50 ug/gm (Ministry of the Environment for Ontario Province) (MOE) and range from 1.0 to 64, based On water hardness, (US EPA, Fed. 49 (26):4553, Feb, 7, 1984). Attachment I includes Tables 1 and 2 from the AMIK report showing the MOE criteria for acceptability of dredged material and the chemical compositions used to designate Great Lakes Barbours as heavily polluted, moderately polluted or nonpolluted. The AMIK study involved an analysis of the water quality, sediment quality, and benthic population for a distance of 8 km downstream of the Maitland Plant as well as a 2 km area upstream of the plant site and a zone immediately downstream of the Du Pont outfall. The results of that study have been, adequately summarised in the %M1K Report? a copy of that summary is attached. Attachment II, Appendices 8-10 of the report contain the information regarding the procedures used in obtaining the data. In Appendix 8 The Shannon-Weaver Diversity Index, which is an accepted procedure for evaluating species diversities, is correctly described. The importarice of this concept to ecologists is that as an area becomes stressed, for whatever reason, the diversity of the organisms capable of living and reproducing in that environment becomes restricted. This restriction means that the population is less able to withstand further insults, the gene pool is more limited, and these additional insults can result in RECEIVED AKK2 3H84 HASKELL .LABORATORY. DUP040011221 a "crash" of the ecosystem. At that point, then, only a very few, extra hardy forms cam survive and these are usually not the desirable species (from commercial or recreational needs). The analytical procedures used to determine the heavy metal concentrations in the water and sediments are described in AMIK, Appendix 10. The methods used are standard and the only unusual feature is a rather high detection limit for lead in sediments (5000 ng/g). This may reflect the small sample size of sediment digested (0.25 g). Data analysis on specific heavy metals indicates that while chromium and zinc are elevated above any of the acceptable standard levels, this is a generalized problem and cannot be associated with Du Pont activities. Nickel, however, had only 9 samples outside of the MOE standard, and 8 of these were downstream of the Maitland Plant outfall. Lead concentrations directly in the outfall sediments were also higher than permitted by either the US EPA or MOE with a mean background concentration of 40 ma/kg, which is 65% higher than noted in the 1975 study. Copper concentrations were also slightly elevated downstream of the Du Pont plant, but this appeared to be somewhat restricted to the deeper sediments. This could reflect earlier practices at the plant or downstream transport from an upstream source. Given the data and information currently available, it is not possible to differentiate between these possibilities. Copper is generally immobile in sediments? this is, it does nfot undergo biological transformations and recycling as do lead, mercury, arsenic, and selenium. The discussion on the biological diversity of the three study zones accurately reflects the data gathered. It does appear that the benthic community has recovered, or at least has not been severely impacted, by the Maitland Plant activities at a point 4 km downstream. There is also no doubt that there is severe biological impact immediately adjacent to the plant outfall. Given, ap historical base, it might be possible to determine, via a modeling effort, whether the zone of influence of the plant outfall is increasing. Since the diversity index increase downstream is gradual and the return to a mixed population not dominated by the oligochaetes (worms) is also gradual, one should foe cautious in estimating the biological zone of impact and in stating that the benthic community has returned to normal levels 4 km downstream. This may be true based on the data in this AMIK study, but the field data should be used to predict the potential of future impact areas and to determine if, indeed, the region 30 m downstream is remaining as the limit of the zpne of biological impact -2- DUP040011222 The second AMIK survey, October 1983, was concerned mote specifically with lead in the water, sediments, benthos, and fish. The MOE guidelines are 25 ppb for lead in the water with a maximum of 50 ppb in drinking water. Lead concentrations in the effluent exceed the former concentration and approximate the latter levels. At 30 m downstream the lead concentrations are 1-6 ppb but they are 4-18 ppb at the 90 m sampling station. This implies an enrichment of lead in the water column, most probably . from release from the sediments. Sedimentary lead levels are 2.5 times above the MOE limits for lead at the plant outfall. This gradually decreases to about one-half the MOE limit of 50 ppb in a plume downstream that includes both deeper sediments and sediments taken at a depth equivalent to the plant outfall. ' The overall organic lead levels are low, <5 ppb, but no limits have been set for organic lead in the environment. It should also be noted that organic lead is more soluble; but, to date, no analyses for it have been made in the water column. It is also this form of lead which is more readily adsorbed by organisms, so the <5 ppb level may be misleading. Analysis of lead in whole fish and fillets of perch and suckers does indeed indicate that a biogoncentration factor (BCF) of approximately 2.5 x l(r and 7.5 x 10 has occurred for fillets and whole fish, respectively. These calculations are based on the fish levels and the mean, downstream water levels of lead atthe 30 m and 90 m sampling stations and do not reflect either the putfall concentrations of lead or lead in the Sediments;. For comparison, fish caught upstreanj of Maitland ^nd analyzed for lead had BCF values of 3.4 x 10 and 4.4 x 10. , and order of magnitude less. Therefore, the AMIK conclusion that the outfall is not contributing to the lead Concentrations in fish is only partially supported by the data they present. Because fish migrate and it is impossible to know their exact swimming and feeding history, one can neither prove or disprove that the lead from the Maitland site is contributing to this problem. Certainly, however, knowing that lead is being released to the river, makes the MOE consider Du Pont a prime; suspect in causing this bioconcentration of lead in commercial fish species. Recommendations; e reduce outfall levels of lead to as low as possible? -3- DUP040011223 e continue to monitor the lead concentrations in the water column, sediments, and fish in the area above the Outfall, at the outfall and at the 30 m and 90 m downstream . stations; begin an examination of the plankton or algae which are growing in these regions as they may be concentrating the lead more than the fish which are then only consuming an already polluted food source; perform on-site biomonitoring with fish to determine the actual BCF under the existing lead and other eiivir.onmental conditions; and, perform sampling under different seasonal conditions, such as winter cold, summer heat, and the typical spring and fall algal blooms. CUL: j ms: 6 CAROL D. LITCHFIELD SECTION SUPERVISOR, ENViRONMENTAL BIOLOGY 4 DUP040011224 TABLE: 1 Attachment I ONTARIO (MOB) CRITERIA OF ACCEPTABILITY TOR OPEN WATER DISPOSAL OF DREDGED MATERIALS* (IWG., 1975: GLWQ BP.1982V VARIABLE MAXIMUM PERMISSIBLE CONCENTRATION Loss on Ignition COD Total Kjeldahl Nitrogen Total Phosphorus (AS P) Mercury Lead Zinc Iron Chromium Copper Arsenic Cadmium Cyanide Ammonia Nickel a. 6% 5.0 g/kg or 5% 2 mg/g 1 mg/g 0.3 mg/kg 50 mg/kg 100 mg/kg 10,000 mg/kg or 1% 25 mg/kg .25 mg/kg 8.0 mg/kg 1.0 mg/kg 0.1 mg/kg 100 mg/kg 25 mg/kg * Analyses mast be on a dry weight basis. IWG 1975 = International Working Group on the Abatement & Control of Pollution from Dredging .Activities GLWQ BD. 19.82 = Guidelines & .Register for Evaluating Great Lakes Dredging Projects (Report to the Great Lakes Water Quality Board) -1.7- DUP040011225 N 29297.01 'TABLE 2a: SPA 1977 GUIDELINES (FROM IJC UPPER LAKES REPORT APPENDIX C) RANGES 'USED TO CLASSIFY GREAT LAKES HARBOURS* VARIABLE COD TEN LEAD ZINC MERCURY NON POLLUTED <40,000 <1,000 <40 <90 <1.0 STATUS MODERATELY POLLUTED 40,000 - 80,000 1,000 - 2,000 40 - 60 90 - 200 (Ranges in mg/kg) y HEAVILY POLLUTED >80,000 >2,000 >60 >200 >1.0 VARIABLE . AMMONIA CYANIDE PHOSPHORUS IRON NICKEL . MANGANESE ARSENIC CADMIUM CHROMIUM BARIUM COPPER TABLE 2bs- SUPPLEMENTARY RANGES (POORER DATA BASE? USES TO CLASSIFY .SEDiMEHT'FROM GREAT LAKES HARBOURS NON POLLUTED <7:5 <0.10 <420 <17,000 <20 <300 <3 * ' <25 <20 .<25 STATUS MODERATELY POLLUTED 75 - 200 0.10 - 0.25 420 - 650 17,000 - 25,000 20 - 50 300 - 500 * 25 - 75 20 - 60 26 - 50 i 00 HEAVILY POLLUTED > 200 >0.25 >650 >25,000 >50 >500 >8 >6 >75 ' >60 >50 (Ranges in. mg/kg Dry `Weight) * Lower limits not: established. -18- DUP040011226 ] 1 Attachment I1 SUMMARY St. Lawrence River water quality, sediment, and benthos were .investigated for an 8 km distance of the river in the vicinity of Du Pont Canada's Maitland Works Plant, Three tones of influence were identified in the study area. The initial or ugstreanii tone located off Maitland village showed water nutrients and bacteria levels within MOE provincial water quality objectives but had heavy metal and nutrient concentrations in the sediment exceeding both MCE guidelines, and reported Lake Ontario Basin averages. The highest benthic diversity and richest species assemblage, specifically Chironomidae occurred at this site. The high benthic diversify may indicate a static deposit of contaminants rather than an active point Source, the second zone of influence occurred in the vicinity of Claybank Bay approximately 2 km upstream from tbe Du Pont outfall. This zone was characterized by ammonia and bacteria at levels well above the MOE guidelines. The highest pseudomonas aeruginosa/ total, and fecal coliform levels recorded in the study occurred in the near shore zone of Claybank Bay. These elevated levels may be an .indication of .an onshore .sanitary waste ' source. Sediment nutrient levels were within MOE guidelines with the exception of one near shore site downstream of claybank Bay- The Chemical Oxygen Demand percentage determined for the Claybank sediments was the survey area maximum with the peak value exceeding the MOE guideline by 300%. The benthic communities in this area represented moderately polluted environmental conditions, A gradual reduction In benthic diversity was npted. The appearance of Manayunkia speciosa and other annelids downstream of the bay was considered to be an indicator of an environmental quality' change. The elevated parameters for water and sediment were thought to be caused by an industrial point source within the Claybank Bay area, The third zone of influence Occurred immediately downstream of the Du Pont outfall. Water quality along the transects was in compliance with MOE guidelines. Sediment, however, showed elevated lead levels above MOE guidelines for a distance of 300 m downstream of the outfall. Elsewhere, -iii- DUP040011227 N 29297.02 lead levels were below the guidelines. The mean lead concentration for the whole Maitland study area based Ph 27 .samples was 23 -2.8 mg/kg. This was lower than the lead values reported in a 1975 MOE study and also lower than the reported mean lead concentration for the whole lake Ontario Basin of 154 +43 mg/kg, Analysis of miking zone wafer samples, 30 m and 90 m downstream of the Du Pont outfall., revealed that, of the 39 parameters checked, phenols / (2-7 jag/L) and copper (3 of 10 samples,- 9-12 jaq/h) exceeded MOE guidelines , The benthic macroinvertebrate diversity was lowest immediately downstream of the Du Pont outfall. This .reduction was coupled with an increase in both the density of Oligochaeta - a tolerant group .and Manavunkia speciosa - an organism indicative of substrate and flow regime .change. The benthic diversity reduction could be the result of turbulent outfall flow and/or chemical effects, J Over the complete study area, organic enrichment coupled with low level effects from industrial point sources influenced the benthic community dynamics. As an example, the absence o..f Bithynla tentaculata was indicative of local environmental stress areas. Complete recovery of the benthos was evident well within the final downstream transect 4 km from the Du Pont outfall. In general, benthic macroinvertebrate species numbers have improved since the 1975 MOE biological survey. -iv- DUP040011228