Conclusions
III
Failure to use a HU approach can set the stage for significant biological and legal problems. Consider, for example, the following scenario. A chronic exposure criterion of 20 Ilg SelL is derived and adopted
for a 10 km segment of river immediately downstream of a municipal
wastewater treatment plant, based on the finding that there are no
toxic impacts to fish, and little bioaccumulation is taking place. However, a few kilometers downstream of this river segment, there is a
250 ha off-channel wetland that is used by wildlife for feeding, spawning, and nesting. Part of the wetland is a public wildlife management
area, and part is under private ownership. The 20 Ilg SelL that is permitted in the river flows into the wetland, bioaccumulates in aquatic
food chains, and causes toxic impacts to fish and bird embryos. Several
questions arise. What is the appropriate criterion for the wetland?
Should it be imposed on the river where no problems are occurring? Is
it prudent to set 2 criteria-one for the river and one for the wetlandwhen the two are hydrologically connected? Who is liable for toxicity
to wildlife, and what recourse is possible for the landowners? Will
litigation be necessary to resolve the dilemma and, if so, what parties
will be involved?
This hypothetical case is becoming a reality in several western states
of the United States as natural resource management agencies, local
municipalities, industry, and private landowners become aware of the
threat selenium poses to fish and wildlife and understand the liabilities that ensue if poisoning occurs (eg, Margolin 1979; Guglielmone
1995). The task of settling "site-specific" criteria issues may involve
complex questions of land and water jurisdiction if the HU affected by
selenium includes several municipalities and counties or crosses state
boundaries. Nevertheless, it is important for natural resource managers to stay focused on the objective of water quality criteria-protection of aquatic life-and not be swayed by those with other interests
whose goals may be totally different. Using the HU method will help
maintain that focus, because it provides an accurate profile of the extent and severity of selenium contamination.
Conclusions
Pollution of aquatic ecosystems by selenium is a growing concern in
the United States and elsewhere around the world (see Chapter 1).
Questions about the appropriateness of using national standards to protect aquatic life at a local level are being raised more and more frequently. Those seeking to develop site-specific water quality criteria
for selenium need to have a clear understanding of how to go about it.
A 2 part process should be followed. This chapter describes the first
III
Failure to use a HU approach can set the stage for significant biological and legal problems. Consider, for example, the following scenario. A chronic exposure criterion of 20 Ilg SelL is derived and adopted
for a 10 km segment of river immediately downstream of a municipal
wastewater treatment plant, based on the finding that there are no
toxic impacts to fish, and little bioaccumulation is taking place. However, a few kilometers downstream of this river segment, there is a
250 ha off-channel wetland that is used by wildlife for feeding, spawning, and nesting. Part of the wetland is a public wildlife management
area, and part is under private ownership. The 20 Ilg SelL that is permitted in the river flows into the wetland, bioaccumulates in aquatic
food chains, and causes toxic impacts to fish and bird embryos. Several
questions arise. What is the appropriate criterion for the wetland?
Should it be imposed on the river where no problems are occurring? Is
it prudent to set 2 criteria-one for the river and one for the wetlandwhen the two are hydrologically connected? Who is liable for toxicity
to wildlife, and what recourse is possible for the landowners? Will
litigation be necessary to resolve the dilemma and, if so, what parties
will be involved?
This hypothetical case is becoming a reality in several western states
of the United States as natural resource management agencies, local
municipalities, industry, and private landowners become aware of the
threat selenium poses to fish and wildlife and understand the liabilities that ensue if poisoning occurs (eg, Margolin 1979; Guglielmone
1995). The task of settling "site-specific" criteria issues may involve
complex questions of land and water jurisdiction if the HU affected by
selenium includes several municipalities and counties or crosses state
boundaries. Nevertheless, it is important for natural resource managers to stay focused on the objective of water quality criteria-protection of aquatic life-and not be swayed by those with other interests
whose goals may be totally different. Using the HU method will help
maintain that focus, because it provides an accurate profile of the extent and severity of selenium contamination.
Conclusions
Pollution of aquatic ecosystems by selenium is a growing concern in
the United States and elsewhere around the world (see Chapter 1).
Questions about the appropriateness of using national standards to protect aquatic life at a local level are being raised more and more frequently. Those seeking to develop site-specific water quality criteria
for selenium need to have a clear understanding of how to go about it.
A 2 part process should be followed. This chapter describes the first