Re-Examination of Mercury Pollution

Journal of GeocHemical Exploration, 29 (1987) 1-12 Elsevier Science Publishers B.V., Amsterdam — Printed in The Netherlands

Environmental geochemical studies

Re-Examination of Hg Pollution in the Ashtabula Area, Ashtabula County, Ohio*

ROBERT A. ANDERSON1 and ERNEST H. CARLSON Department of Geology, Kent State University, Kent, OH 44242, U.S.A. (Received May 14,1986)

ABSTRACT '

Andersen, RA. and Cartson, E.H., 1987. Re-examination of Hg pollution in the Ashtabula area, Ashtabula County, Ohio. In: R.G. Garrett (Editor), Geochemical Exploration 1985. JgGeochem. Explor., 29:1-12.

Environmental concern about Hg pollution in Lake Erie peaked in 1970 with most, investiga- tions being directed to the west end of the lake and problems associated with Lake Si.' Clair. The Ohio Geological Survey subsequently (1970-1971) collected and analyzed stream and lake sediments in the vicinity of several industrial areas that border Lake Erie and reported indications of Hg pollution along the lower reaches of the Ashtabula River. Neither the intensity, nor the center, of the contamination was recognized in that study. In 1970, however, the state began to monitor the levels of Hg in the industrial effluent of the area. During a re-investigation of pollution at Ashtabula, 68 sediment samples were collected across an area of 90 km2 in the late spring and early summer of 1982. The Hg that was released by heating the samples on a hot plate for one minute at 290 °C was determined with a gold-film Hg detector. "£"££^ Mercury concentrations in the sediments had a median (background) value of 24.4 ppb and a &:•*£« mean content of 422 ppb, and exhibited a lognormal distribution that was bimodal. Three samples that ranged from 1550 to 20,600 ppb Hg are considered anomalous and come from the drainage of Fields Brook. Although no single industrial operation could be targeted as a source, high Hg levels apparently are due to the past accumulation of industrial waste. Mean Hg levels in the Ashtabula River samples from south and north of the junction with Fields Brook were 42.8 and 118.5 ppb Hg, respectively, indicating that contamination of the latter had occurred. The Lake Erie samples (mean ppb Hg) can be separated by the mouth of the Ashtabula River and the depth of the lake bottom as follows: west side (9.7),east side (59.8); and shoreline (15.8), nearshore (64.5). The six-fold increase on the eastern side of the harbor relative to the western side is believed to be due to the direction of the longshore currents which, in the Ashtabula area, run from southwest to northeast. The four-fold increase in Hg levels in nearshore sediments relative to those from the shoreline is due to preferential concentration in the finer size fraction. The Hg levels obtained for nearshore sediments just east of the Ashtabula River are six times higher

•Contribution No. 299, Department of Geology, Kent State University. 'Present address: 2916 Fairview Drive, Ashtabula, OH 44004, U.S.A.

!• .' X**PlMHtt. lMSi.'i.Vit »"."« «..S»"-U' • ' V.'., than those reported earlier by the Geological Survey, suggesting that accumulation of Hg may have occurred.

INTRODUCTION

The accumulation of Hg in the environment from industrial wastes has become a worldwide problem due to the toxic character of that element (D'ltri and D'ltri, 1977). Environmental concern about industrial Hg pollution in Lake Erie peaked in 1970, when high levels discovered at the western end of the lake could be traced to contamination from Lake St. Clair (Fig. 1). In the Ashtabula area at that time, reports confirmed that Hg-rich waste water had been dumped into ponds and ditches entering Fields Brook and Lake Erie (The Star-Beacon, 1970a, b, c). The Ohio Geological Survey subsequently (1970- 1971) collected and analyzed stream and lake sediment from the Ashtabula region, as well as from several other industrial areas that border on the southern shore of Lake Erie (Stith, 1973). Although signs of Hg pollution along the lower reaches of the Ashtabula River were documented in that study, neither the intensity nor the center of the contamination was recognized. A few years later local residents expressed concern to one of the investigators (H.A.A.) about high levels of Hg that reportedly were encountered in old drainage pipelines at Fields Brook. An additional problem was the quality of municipal water, which is drawn from the lake through an aqueduct on the west side of the harbor. Although industrial effluent at Ashtabula continues to be discharged into Fields Brook and Lake Erie (Fig. 2), Hg loads today are maintained at minimal levels as specified in discharge permits issued under the authority of the Clean Water Act (Ohio Environmental Protection Agency, unpublished data). Undesirable amounts of Hg, therefore, may still be entering the lake from old disposal sites or past spills at Ashtabula, even though the discharge of toxic constituents from other areas along the lake has been reduced greatly over the past 15 years (Herdendorf and Stuckey, 1979). The purpose of the present study was to determine the extent and source of Hg contamination in the drainage sediment of Ashtabula and adjacent parts of Lake Erie v^y^$^;V:;;~y . by means of a detailed program of sampling and analysis. The Ashtabula area is situated within the southern part of the Lake Plains province and is underlain by glaciolacustrine silts and clays which, in turn, rest on glacial till. Both surface drainage and groundwater generally flow north- ward into the Lake Erie basin. Fields Brook runs westerly through the industrial district of Ashtabula Township before it enters a residential area at the eastern city limits and empties into the Ashtabula River, the latter draining into the lake at Ashtabula Harbor. The shore at Ashtabula trends east-northeast and is characterized by bluffs up to 20 m high and deep stream channels, exposing the glacial deposits and the underlying Devonian black shales.

* 4^r$>r-">;. ;=;, •'• '•"' -•'V'.Vi.rV'fr.rv. '•^£^i*3»rp?TT£rs>;;'?X :'&£2HEt9;&&:il4 '$8 S'.t.' ?V ;.'.-' V 1 •S^ii'JLr •- ~ ' ••^K*

Fig. 1. Map of Lake Erie showing the location of the Aahtabula area.

SAMPLE COLLECTION, PREPARATION AND ANALYSIS

Sixty-eight grab samples were collected across a region of 90 km2 during the late spring and early summer of 1982 (Fig. 2; Tables 1 and 2). As the complex of industrial and chemical plants is situated in the central part of the study area, the drainage there and in the surrounding vicinity contains the highest density of sample sites. The bodies of water that were sampled and the corre- sponding number of sites visited were as follows: Fields Brook (5), Red Brook (5), Whitman Creek (5), the Ashtabula River (22), Lake Erie (27), ponds (2) and drainage ditches (2). Most stream sediment samples were collected from active portions of the channels near road crossings. Lake Erie shoreline samples (16) were gathered at average water depths of 0.3 m, while nearshore ones (11) were obtained at depths ranging from 1.5 to 4.7 m. Nearshore sediment, which provides about a meter of veneer west of the harbor and a few centimeters on the east side, was obtained by scuba diving. The samples typi- cally were dark brown to gray, organic, sandy muds except for the shoreline sediment which consisted of gray and brown sands (Tables 1 and 2). The samples were air-dried, sieved to — 80 mesh (—177 /on) and stored in tightly capped vials for analysis. The weight of the material analyzed varied according to the Hg content and ranged from 1.0 to less than 0.1 g. A partial extraction technique was selected in the present study because Hg in the Ash- tabula sediment is believed to be bonded loosely. The precision of ±20%, as measured by the relative standard deviation, was surprisingly good for an apparatus that was readily portable. The Hg was released by heating the samples on a hot plate for one minute at 290 °C and the resulting vapor analyzed with a Jerome Instrument Corporation Model 301, gold-film Hg detector (McNerney, 198la, b). The amount of Hg yielded by this method is propor- tional to the concentration in the samples, being about 40% of the total on average. The instrument has an absolute sensitivity of 1.0 ng of Hg (McNerney, 1983). All samples were run at least twice with the mean values being recorded. / A K E ERIE

••#•;.•. #*, •.]

._'.- - .^r.*•**'• jmi TABLE 1

Location and description of the stream, ditch and pond samples

Station Location Sample deacriptkm MeanHg oo. content (ppb) A-l Ashtabula River on north side of State Road bridge Brownish -gray sandy mud 13.4 A-2 Aahtabula River on east tide of Ohio Rout* 11 overpass Brownish -gray Mndy mud 4.0 A-3 Ashtabula River near nwuth of Hubbard Run Brownish-gray sandy mud 93 A-4 Aahtabula River south of Norfolk «od Western railroad bridge Brownish-gray sandy mud 90.5 A-5 Aahtabula River north of Norfolk and Western railroad bridge Brown sandy mud 6.6 A -6 Ash tabula River north of Ohio Route 20 Brownish-gray mud 68.2 A-7 AahtabukRrw on weat side of Hannon Hill bridge Brown organic mud 90.5 A-8 Aahtabula River on Moth side of Bast 24th St. bridge Brown sandy mud 4.2 A-9 Asbtabula River on northeaat «de of But 24th St. bridge Brown organic mud 16.6 A- 10 Ashtabula River on northwest tide of But 24th St bridge Black organic mud 32.9 A-ll Ashtabula Rivw on south side of Fields Brook mouth Black organic mud 111 A-12 Ashtabula River at month at FieUi Brook Gray organic mud 63J A-13 Aahtabula River north of Pena Central railroad bridge Brown organic mud 296 A-H Ashtabula River south of Ashtabula Yacht Club Brown organic mud 46.3 A-16 AshtabuU River south of Middle Road bridge Gray sandy mud 329 R-l Red Brook on north side of Lake Road bridge Brown sandy mud 10.0 R-2 Red Brook mouth Brownish-gray sandy mud

Location and description of the lake samples

Station Location Water Sample MeanHg no. depth description content (PI*) S-l Shoreline west of north end of Maple Drive 0.3m Brownish-tray sand 12.3 S-2 Shoreline near north end of Elm Drive 0.3m Grayish-brown sand 20.6 S-3 Shoreline near west end of Overlook Drive 0.3m Dark gray sand <1 3-4 Shoreline near north end of Oak Drive 0.3m Dark pay tend 1.7 3-5 Shoreline near east end of Edfewtter Drive 0.3 m Gray muddy send 1.4 S-6 Shoreline near weet end of Walnut Beach Park 0.3m Browniah-tray sand 1.7 S-7 Shoreline near weet eide of met harbor 0.3m Brown muddy sand 16.S breakwater S-8 Shoreline eaet of weet harbor breakwater 0.3m Browniah-gray sand 2.3 3-9 Shoreline weet side of amaB embayment 0.3 n Gray muddy sand U 3-10 Shoreline between two drain*** pipeline* 0.3m Gray send 67.7 S-ll Shoreline on east side of Met drainage pipeline 0.3m Gray sand 38.3 S-I2 Shoreline on weet aide of weet drainage pipeline 0.3m Grayish-brown send 30.0 S-13 Shoreline eaet of Whitman Creek mouth 0.3 ta Gray muddy sand 14.1 3-14 Shoreline on west eide of Kingsvifle On-the-Leke OJm Gray sand 20.6 S-15 ShoreHne at Whitman Creek mouth 0.3m Brown muddy sand 20.8 3-16 Shoreline weet of Whitman Creek mouth OJm Dark (ray sand • 2.6 N-l Offshore 0.7 km and weet of Red Brook mouth 3.7m Brown sandy mud 10.5 N-2 Offshore 0.7 km from Red Brook mouth 4.3m Brown sandy mud 63.2 N-3 Offshore 0.8 km and eaet of Red Brook mouth 4 .6n Grayish-brown sandy mud 2.1 N-4 Ofbhora 0.4 km from eaet end of Walnut Beach 3.0m Brownish -pay sandy mud 1.8 Park N-5 Offshore 0.6 km and eaet of eaet breakwater 4.0m Light gray sandy mud S9A N-6 Offshore 0.2 km and west of weet drainage 1.6m Gray offanic sandy mud 24.4 pipeline N-7 Offshore 0.2 km between two drainage pipeline* 2.4m Grey organic sandy mud 372 N-8 Offshore 0.2 km and east of east drainage pipeline 1.8m Brown mud '• 149 N-9 Offshore 0.3 km and weet of Whitman Creek 1.8m Brownish-fray sandy mud 10.7 mouth N-10 Offshore 0.3 km from Whitman Creek mouth 2.4m Gray organic mud 21.2 N-ll Offshore 0.3 km and eaet of Whitman Creek 2.1m Gray sandy mud 6.2 mouth

RESULTS OF THE INVESTIGATION Mercury concentrations (ppb) in the sediments ranged from < 1 to 20,600,

; - , -. i''W.-<'•"; J?. *f'?,-••-.-^L-**.•-.• •« . •-'••''• -,.•-„,^i•?. '?"->.-.*'', •- with a median value of 24.4, an arithmetic mean content of 422 and a standard deviation of 2510. The mean value was somewhat higher than comparable results of Shackletteetal. (1971) andStith (1973), due to the presence of high - ""^^^?!^-C':V^!' ! concentrations of Hg in a few samples (Table 3). For this reason the median ;- v *•<--'-.- <• '';,-'-•-" -• • ' • \U:i?i•-•^vuv'Vf •*?.**:*-' "-' - ,•" ;" ' is believed by the writers to be the best estimate of the average background for the region. The data showed a lognormal distribution that was bimodal. The threshold was determined from a plot of cumulative frequency (percent) for log Hg concentrations (Fig. 3). Using Sinclair's (1976) method, the projection of the line that represented the background population at the 2% level of cumulative frequency yielded a threshold value of 1500 ppb Hg. The background population, which is based on 96% of the data, displayed values that ranged as high as 494 ppb Hg, with those at the upper end of that range being derived from both natural and industrial sources of Hg. Mean and median values of Hg (ppb) in the different areas (Fig. 4) are presented in Table 4. The anomalous samples were restricted to Fields Brook, clearly pinpointing o o o o o

3.0

- \ , Q>

2.0 - Background ' 1 Poi ulation \ - \, V

0.5 C \ \ 10 ' 30 50 70 90 96 99 Cumulative Frequency ( Fig. 3. Plot of cumulative frequency (%) vs log Hg (ppb) in stream and lake sediments. that drainage as the major source of Hg pollution in the Ashtabula area at the time of this study. The highest value (20,600 ppb Hg, Station F-2) was obtained in sediment along the west side of State Road at the western edge of the industrial complex. No single property could be targeted as a center of contamination, however, since the anomalous samples did not form a pattern of values that systematically decayed downstream. Fields Brook is characterized by a relatively high gradient and has cut a narrow ravine to its junction with the Ashtabula River, except for a small area west of State Road where the channel floor is wider. Of the samples from the Ashtabula River, 16 obtained from the upstream, or to the south, of the junction with Fields Brook and a mean value of 42.8 ppb Hg, while six from the downstream (north) side yielded a mean

TABLE 3

Comparison of the Hg content (ppb) in the sediment samples with data of other workers

Present work Stith (1973)' Shacklett*(1971)b Range < 1-20,600 < 1-535 10-3,400 Arithmetic mean 422 158 147 Median 24.4 18.3 Geometric mean 96 Number of samples 68 17 420 "Based on the arithmetic means of the Ashtabula sites. bSoil samples from the eastern United States. TABLE 4 Mean and median Hg contents (ppb) and sample sizes, n, for drainage basins of the Ashtabula area

Locality Hg, ppb mean median n

,.... •. . . ..• - . , Fields Brook 5,100 1,550 5 Red Brook 64.1 10.0 5

**JSwT*C.*?rt.i41-.*...'*^ fY^i^nrv .-r ' Whitman Creek 39.5 32.8 5 Ashtabula River 63.8 46.3 22 Lake Erie 35.6 14.1 27 Ponds 98.1 - 2 Ditches 64.4 - 2

content of 120 ppb. Using a one-sided t-test and a pooled estimate of the standard deviation (Crow et al., 1960), the difference in mean values was found to be significant at the 2.5% level. This result indicates that a significant com- ponent of the Hg in the sediment of the lower reaches of the Ashtabula River has been added from Fields Brook. The Lake Erie sediment samples can be separated by the mouth of the Ash- tabula River and the depth of the lake bottom into two pairs of data (Table 5). These data reveal a six-fold increase in mean Hg content on the eastern side of the harbor relative to the western side, and an increase by factor of four in the mean of the nearshore sediments as compared to the shoreline samples. Significant differences in the mean values for both sets of data were obtained at the 5% level when the t-test (see above) was applied. The first of the two relationships indicates that Hg has contaminated the lake sediments east of the harbor, the possible sources of this mercury will be discussed later. With respect to the second comparison, the higher concentrations of Hg in nearshore sediment relative to those in the shoreline samples are due to the preferential accumulation of that element in the finer grain size fraction. This *fi*ge'T'r-V'S tf£S;<-.^-;v. fWW-V-"- results agrees with the findings of de Groot et al. (1971), who showed that Hg »a,&V-."•' i• and other heavy metals are concentrated in the smallest size fractions of -'1 1 . '- • -& sediments.

DISCUSSION

The anomalous Hg values that were obtained in this study are apparently due to past industrial activity east of the city. In this regard, effluent from the Ashtabula industrial complex has followed two drainage routes for many years, one entering Fields Brook and the other Lake Erie. Industrial discharge into Fields Brook and its tributaries has occurred at several points over a distance of about 2 km and, in the past, the effluent has polluted the water and air, and LAKE ERIE

-oClJ T H S H\ P

Fig. 4. Map of the study area showing the distribution of Hg (ppb) in stream and lake sediments. 10

TABLES

Mean and median Hg contents (ppb) and sample sizes, n, for Lake Erie sediment samples

Locality Hg, ppb

mean median n West of Ashtabula Harbor 9.7 2.1 13 East of Ashtabula Harbor 59.8 21.1 14 Shoreline 15.8 12.3 16 Neanhore 64.5 21.1 11

killed vegetation alongside the main channel (The Star-Beacon, 1972). Begin- ning in 1970, Hg levels in the waste water were greatly reduced, but the stream bed and many of the sludge ponds and ditches emptying into it were not cleaned up. Correspondingly, the stream sediment along Fields Brook was found to contain high levels of Hg during the present investigation. The second system, referred to here as the Lake Erie route, drains the area northeast of Fields Brook and consists of a northerly flowing network of ditches, pipelines and tailings ponds (Fig. 4). The Hg levels in waste water from this system were drastically reduced in 1970, and suspected polluters there were required to uti- lize new ditches to the lake and to clean up contaminated ponds and drainage lines (The Star-Beacon, 1970b). The results that are reported in this paper did not identify any sites of anomalous Hg along the Lake Erie route, or in the lake sediment adjacent to its outfall. Sediment from recent industrial discharge, thus, yields Hg levels in the background range, while it is the past disposal sites in and along Fields Brook and contaminated sediment downstream from them, that are the chief sources of Hg threatening the environment. The lake sediment on the east side of the harbor has been shown by the writers to be moderately enriched in Hg, and the origin of this Hg is of great environmental concern. Possible sources of this contamination, as discussed above, include: (1) Hg-rich material that had been eroded from the banks of Fields Brook and deposited in the harbor, and (2) effluent that had been trans- ported to the lake along the Lake Erie route. The lake floor is shallow in the nearshore zone and, due to longshore currents (Alther, 1981; Carter and Guy, 1983), the transport path of the lake sediment is toward the northeast. Of the two sources, Hg-rich material from Fields Brook has been dispersed downstream, contaminating the sediment of the Ashtabula River. Sediment in Ashtabula Harbor contains a number of hazardous substances that also can be traced to Fields Brook (U.S. Environmental Protection Agency, 1983). Trans- port of the polluted harbor material toward the northeast, however, would be slowed by the harbor breakwaters. In addition, a channel in the harbor is maintained for transport vessels, and the practice of dumping sediment dredged

fe^'iWtRfffl^-^ - ^>ifll« 11 from this channel into deeper water over the years (Alther, 1981) has compli- cated the dispersal of the contaminated harbor sediment further. The second of the possible sources is more problematical, since no anomalous Hg was found associated with it. Effluent that had been discharged into the high-energy nearshore environment would have mixed with the lake sediment and been subjected to northeastward transport. This effluent would have been characterized by higher Hg loads prior to 1971, due to the lax pollution laws existing at that time, and lower loads between 1971 and the present. Pre- sumably, if pre-1971 outfall had been the dominant source of contamination in the lake sediment, concentrations of Hg would have decreased continuously up to the present because of transport by longshore currents. If recent replen- ishment of Hg had occurred, on the other hand, from Fields Brook, variations of Hg levels in the lake sediment over the years probably would have been erratic or even have increased Some mercury may have accumulated in the nearshore sediments east of Ashtabula during the time interval separating sample collection by the present investigators, in 1982, and by Stith, in 1970. The argument supporting accumulation, however, is not a strong one since it is based on the comparison of Hg values that were obtained in different laboratories by different analytical methods. The mean Hg level obtained for seven nearshore lake sediment samples on the east side of the harbor (91.8 pp), is seven times higher than the mean value of 11.9 ppb Hg that was determined in five samples from the same vicinity by Stith (1973). Although the difference in mean values did not prove to be significant when tested at the 5% level (significance first appeared at the 15% level), the negative result may be due to the small number of samples being compared Nevertheless, insufficient data are available to demonstrate convincingly that Hg levels have increased over the 12-year period. Accord- ingly, the Hg contamination in the lake sediment could not be narrowed to a specific source, although the majority of the evidence obtained in this study points to a Fields Brook supply rather than one from the Lake Erie route. The outlook for the environmental recovery of the Fields Brook-Ashtabula Harbor area is favorable. A partial turn-around in the conditions along Fields Brook has been noted recently. This has been brought about by state and federal mandated limits on the loads of industrial pollutants entering the drainage. In September, 1983, Fields Brook appeared on the National Priorities List of localities where hazardous substances are believed to pose a threat to human health and the environment, although the area was not ranked as a top priority site for cleanup operations (U.S. Environmental Protection Agency, 1984). Subsequently, a remedial investigation/feasibility study at Fields Erode by the Environmental Protection Agency has begun. The plans of the USEPA for removing the toxic constituents, however, have not been announced yet. As the work of the present investigators points out, excessive levels of Hg continue

**1 7>' ••'• : sr™*l :W. #•*"*£• •^ 1 '* i^ ?' 12 to be discharged into Lake Erie at Ashtabula from past industrial accumula- tions. The timely cleanup of Fields Brook is imperative.

.'-. . ." -',v i; '"•-'.•'.-"', -X ; ACKNOWLEDGEMENTS The Hanna Mining Company, Cleveland, Ohio, provided partial funding for the gold-film Hg detector. Discussions with staff members of the Northeast District Office of the Ohio Environmental Protection Agency, Twinsburg, proved to be invaluable to the investigators in writing this paper. Karen Taylor did the drafting.

REFERENCES

Alther, G.R., 1981. Transport of dredged sediment after disposal operation in Lake Erie. Ohio J. Set., 81:2-8. Carter, C.H. and Guy, D.E., Jr., 1983. Lake Erie shore erosion, Ashtabula County, Ohio: letting, processes and recession rates from 1876 to 1973. Ohio Div. Geol. Surv., Rep. Inv, 122,107pp. Crow, E.L., Davis, F.A. and Maxfield, M.W., 1960. Statistics Manual. Dover Pub. Inc., New York, N.Y.,288pp. D'ltri, P.A. and D'ltri, F.M., 1977. Mercury Contamination: a Human Tragedy. Wiley and Sons, New York. N.Y., 311 pp. Groot, A.J. de, Goejj, JJ.M. de and Zegers, C,, 1971. Contents behavior of mercury as compared with other heavy metals in sediments from the riven Rhine and Ems. Geol. Mijnbouw, SO: 393-398. Herdendorf, C.E. and Stuckey, R.L., 1979. Lake Erie and the islands. In: M.B. Lafferty (Editor), Ohio's Natural Heritage. Ohio Acad. Sci., Columbus, Ohio, pp. 215-235. McNerney, J,J., 198la. Description and operating instructions for Model 301, gold film mercury detector. Jerome Instrument Corp., Jerome, Ariz., 25 pp. McNerney, J .J., 1981b. Application note: low-temperature analysis of soils usinga Jerome Instru- ment Corporation Model 301 gold Him mercury detector. Jerome Instrument Corp., Jerome, Ariz., 5 pp. McNerney, R.T., 1983. Analysis of mercury using a gold film detector. Am. Lab.. 15:64,66,70. Shacklette, H.T., Boerngen, J.G. and Turner, R.L., 1971. Mercury in the environment; surficiaJ materials of the conterminous United States. U.S. Geol. Surv., Circ. 644,5 pp. Sinclair, A J., 1976. Application of probability graphs in mineral exploration. Assoc. Explor. Geo- chemists, Spec. Vol. 4,95 pp. The Star-Beacon, 1970a. Ohio: Detrez mercury wastes "very small". The Star-Beacon, Ashtabula, Ohio. April 14,1970, pp. 1-2 The Star-Beacon, I970b. Detrex stops mercury flow. The Star-Beacon, Ashtabula, Ohio, July 16, 1970, p. 1. The Star-Beacon, 1970c. Plant mercury flow down, Hickel sees lake cleanup. The Star-Beacon, Ashtabula, Ohio, Sept. 17,1970, p. 1. The Star-Beacon, 1972. New Ohio pollution head vows Fields Brook cleanup. The Star-Beacon. Ashtabula Ohio, July 29,1972, p. 1. Stith, D.A., 1973. Mercury concentrations in sediments of the Lake Erie Basin, Ohio. Ohio Div. Geol. Surv., Inf. Circ. 40,14 pp. U.S. Environmental Protection Agency, 1983. Fields Brook, Ashtabula, Aahtabula County, Ohio: Documentation record for site 227. U.S. Environmental Protection Agency, Washington, D.C., 18pp. U.S. Environmental Protection Agency, 1984. Amendment to National Oil and Hazardous Sub- stance Contingency Plan; National Priorities List. Federal Register, 49 (185): 37070-37090.

.'^:^^Kiim!S:' . •- •.:'-.-"• r'&tSPlZ^S''.-'• •,. ,<•-•;]'•*/.?•"-" :. '*';-#,»••