92
R.R. Turner and G.R. Southworth
on mercury-mining sites (only two are described), or mining sites where mercury
was employed to extract precious metals. Other chapters in this Volume cover
examples of the latter sites (e.g., Lechler et al., this vol.). Nor will we discuss the
numerous small sites contaminated by spills from mercury manometers
associated with natural gas production and transmission systems (see review
by Henke et al. 1993). The authors have an extended period of direct experience
with two sites (Oak Ridge, Tennessee, and Saltville, Virginia) and thus more detail
is presented for these sites.
2
Example Sites and Case Studies
2.1
Lake St. Clair
The st. Clair River forms the uppermost portion of the aquatic system between
Lake Huron and Lake Erie. This river, and Lake St. Clair and the Detroit River to
the south, are part of an important international waterway. Findings here related
to mercury in fish in 1970 led ultimately to the first comprehensive assessment of
the impact of mercury releases to aquatic systems and to the first regulation of
such discharges in North America. Two chloralkali plants using mercury cells
operated along this waterway in 1970 and collectively were discharging kilogram
quantities of mercury on a daily basis. Both facilities immediately began
aggressively reducing their discharges, with the result that concentrations in fish
in the receiving aquatic system decreased rapidly over the next few years (Fig. 2).
Eventually, both facilities discontinued the use of mercury cell technology, but no
published information could be found describing how on-site contamination at
the plant sites was addressed. Mercury in 45-cm walleye in the lake continued to
decline through the mid-1980s (Fig. 2), but still exceeds the Canadian limit for
fish sold commercially (0.5 ~Lg g-') and engenders advisories to sport fishermen
to limit consumption of larger fish. Walleye of the same size collected upstream
(southern Lake Huron) ranged from 0.41 to 0.25 pg g-' between 1981 and 1992
(Scheider et al., in press) and showed no temporal trend. In addition, concerns
persist about the inventory of mercury in sediment downstream of these sites.
2.2
Abbotts Creek/High Rock Lake, North Carolina
Elevated concentrations of mercury were found in 1981 in the sediments (up to
9.5 ~Lg g-') and fish (up to 3.0 pg g-', 30% exceeding 1.0 pg g-' limit) in the
Abbotts Creek embayment of High Rock Lake, a 39-km2 hydroelectric reservoir
in central North Carolina (Miller 1983; NCDEHNR 1993). The contamination was
traced to a battery manufacturer in the watershed and resulted in issuance of a
R.R. Turner and G.R. Southworth
on mercury-mining sites (only two are described), or mining sites where mercury
was employed to extract precious metals. Other chapters in this Volume cover
examples of the latter sites (e.g., Lechler et al., this vol.). Nor will we discuss the
numerous small sites contaminated by spills from mercury manometers
associated with natural gas production and transmission systems (see review
by Henke et al. 1993). The authors have an extended period of direct experience
with two sites (Oak Ridge, Tennessee, and Saltville, Virginia) and thus more detail
is presented for these sites.
2
Example Sites and Case Studies
2.1
Lake St. Clair
The st. Clair River forms the uppermost portion of the aquatic system between
Lake Huron and Lake Erie. This river, and Lake St. Clair and the Detroit River to
the south, are part of an important international waterway. Findings here related
to mercury in fish in 1970 led ultimately to the first comprehensive assessment of
the impact of mercury releases to aquatic systems and to the first regulation of
such discharges in North America. Two chloralkali plants using mercury cells
operated along this waterway in 1970 and collectively were discharging kilogram
quantities of mercury on a daily basis. Both facilities immediately began
aggressively reducing their discharges, with the result that concentrations in fish
in the receiving aquatic system decreased rapidly over the next few years (Fig. 2).
Eventually, both facilities discontinued the use of mercury cell technology, but no
published information could be found describing how on-site contamination at
the plant sites was addressed. Mercury in 45-cm walleye in the lake continued to
decline through the mid-1980s (Fig. 2), but still exceeds the Canadian limit for
fish sold commercially (0.5 ~Lg g-') and engenders advisories to sport fishermen
to limit consumption of larger fish. Walleye of the same size collected upstream
(southern Lake Huron) ranged from 0.41 to 0.25 pg g-' between 1981 and 1992
(Scheider et al., in press) and showed no temporal trend. In addition, concerns
persist about the inventory of mercury in sediment downstream of these sites.
2.2
Abbotts Creek/High Rock Lake, North Carolina
Elevated concentrations of mercury were found in 1981 in the sediments (up to
9.5 ~Lg g-') and fish (up to 3.0 pg g-', 30% exceeding 1.0 pg g-' limit) in the
Abbotts Creek embayment of High Rock Lake, a 39-km2 hydroelectric reservoir
in central North Carolina (Miller 1983; NCDEHNR 1993). The contamination was
traced to a battery manufacturer in the watershed and resulted in issuance of a