116
7. Developing Site-Specific Water Quality Criteria
nium, perhaps to thousands of times the waterborne concentration,
but are unaffected by tissue residues that are high enough to cause
reproductive failure when consumed by fish and aquatic birds (Lemly
1985a). Thus, bioaccumulation in aquatic food chains, and dietary transfer to eggs causes otherwise harmless concentrations of waterborne
selenium to become toxic. Establishing water quality criteria that prevent this degree of bioaccumulation in aquatic food chains is the goal
of the procedure given in this chapter.
Information concerning the presence or absence of reproductive effects, coupled with information on the degree of accumulation in major
ecosystem components, can be used to precisely evaluate local conditions
and derive an appropriate site-specific water quality criterion for selenium. This process can be applied consistently and uniformly, regardless
of location or habitat type-that is, in wetlands (seasonal or permanent),
streams, rivers, lakes, reservoirs, and other impoundments.
Procedure
Step 1
The first step is to gather information on selenium residues and biological effects. This is done to provide an empirical foundation for evaluating a criterion, which may be national, state, or local, and which
FIGURE 7.1. A decision tree for determining if modification of a selenium water
quality criterion is necessary. Numbers indicate the following: 1, a sufficient
number of samples to provide some spatial and temporal integration, collected across a Hydrological Unit (see Chapter 6); 2, possible problem suspected based on observations and available information collected from the
Hydrological Unit; 3, measure and interpret according to guidelines and procedures given by Skorupa and Ohlendorf (1991) and Lemly (Chapters 2 and 3);
4, residues that equal or exceed the toxicity thresholds given in Table 7.1; 5,
down-gradient impacts to other aquatic systems, wetlands, or selenium sensitive species in the Hydrological Unit, induding confluence with receiving waters that cross state lines or other jurisdictional boundaries; 6, teratogenic
deformities and/or embryomortality, measured according to guidelines and
procedures given by Ohlendorf et al. (1986a, 1986b, 1988), Hoffman et al.
(1988), and Lemly (1993b) (see also Chapters 2,3, and 5); 7, modify according to procedures given in the text; 8, monitor for evidence of teratogenic
deformities and/or embryomortality, and associated selenium residues in eggs,
embryos, and larvae; 9, regulatory and management actions to effectively control or modify the source in order to reduce selenium inputs.
7. Developing Site-Specific Water Quality Criteria
nium, perhaps to thousands of times the waterborne concentration,
but are unaffected by tissue residues that are high enough to cause
reproductive failure when consumed by fish and aquatic birds (Lemly
1985a). Thus, bioaccumulation in aquatic food chains, and dietary transfer to eggs causes otherwise harmless concentrations of waterborne
selenium to become toxic. Establishing water quality criteria that prevent this degree of bioaccumulation in aquatic food chains is the goal
of the procedure given in this chapter.
Information concerning the presence or absence of reproductive effects, coupled with information on the degree of accumulation in major
ecosystem components, can be used to precisely evaluate local conditions
and derive an appropriate site-specific water quality criterion for selenium. This process can be applied consistently and uniformly, regardless
of location or habitat type-that is, in wetlands (seasonal or permanent),
streams, rivers, lakes, reservoirs, and other impoundments.
Procedure
Step 1
The first step is to gather information on selenium residues and biological effects. This is done to provide an empirical foundation for evaluating a criterion, which may be national, state, or local, and which
FIGURE 7.1. A decision tree for determining if modification of a selenium water
quality criterion is necessary. Numbers indicate the following: 1, a sufficient
number of samples to provide some spatial and temporal integration, collected across a Hydrological Unit (see Chapter 6); 2, possible problem suspected based on observations and available information collected from the
Hydrological Unit; 3, measure and interpret according to guidelines and procedures given by Skorupa and Ohlendorf (1991) and Lemly (Chapters 2 and 3);
4, residues that equal or exceed the toxicity thresholds given in Table 7.1; 5,
down-gradient impacts to other aquatic systems, wetlands, or selenium sensitive species in the Hydrological Unit, induding confluence with receiving waters that cross state lines or other jurisdictional boundaries; 6, teratogenic
deformities and/or embryomortality, measured according to guidelines and
procedures given by Ohlendorf et al. (1986a, 1986b, 1988), Hoffman et al.
(1988), and Lemly (1993b) (see also Chapters 2,3, and 5); 7, modify according to procedures given in the text; 8, monitor for evidence of teratogenic
deformities and/or embryomortality, and associated selenium residues in eggs,
embryos, and larvae; 9, regulatory and management actions to effectively control or modify the source in order to reduce selenium inputs.