LAW vs The Water Boards: How to Weaken Water Standards
The Water Boards’ resolutions we are challenging replace the existing Water Quality Standards for copper and lead in the Los Angeles River and its tributaries with “Site Specific Water Quality Objectives” or SSOs. The Clean Water Act establishes water quality standards that are national in character, aimed at protecting the designated uses of a “generic” waterbody. But the effects of pollution on a concrete (no pun intended) waterbody like the LA River can vary greatly from the effects of pollution on the generic waterbody because of differences in local water chemistry and biochemistry, and differences in aquatic communities compared to the generic waterbody. Local river (bio)chemistry and biology is also dynamic, constantly varying (sometimes tremendously) across even small spatial distances and over short time intervals.
Recognizing these potentially significant variations, federal regulations implementing the Clean Water Act allow for substitution of national standards with standards tailored for much smaller geographical areas, provided appropriate studies are undertaken. In this case, the study area includes most of the LA River and its tributaries, and that area is further broken into smaller subareas such as, for example, Rio Hondo and LA River Reach 3.
In theory, the use of more localized standards is appropriate, perhaps in some cases even preferable, because site specific objectives, by their nature, can be more tailored to the distinct challenges of copper and lead pollution faced by the LA River system.
As we will discuss, the devil resides in the details, and let’s just say the demons are frolicking from Tujunga to Long Beach as a result of SSOs that allow up to 969% more copper and up to 1,351% more lead than the Water Quality Standards they replaced. But I digress. Today’s article is to provide the background needed to understand what an SSO is.
Where did these SSOs come from?
The federal Environmental Protection Agency (EPA) recognizes three different primary methodologies to calculate SSOs for most toxic pollutants, and a fourth methodology specific to copper. Those methodologies are the “Recalculation Procedure,” the basis for the lead SSOs now at issue, the “Water Effect Ratio Procedure” and the “Streamlined Water Effect Ratio for Copper,” both of which were used to derive the copper SSOs at issue, and the “Resident Species Procedure” which is not at issue in the current lawsuit.
A Recalculation Procedure is a series of statistical and mathematical operations performed on “data sets” approved by EPA, the raw data used to empirically derive the equations that set out lead standards. The data sets are basically dose-response curves for lead for various aquatic species accepted as scientifically defensible by EPA. When the equations were last calculated nationally – decades ago – many of these data sets were not available. The Recalculation Procedure derived Site Specific Objectives for lead in the LA River by recalculating individual empirically derived terms based on the new national “data sets” approved by EPA, so in that respect there is nothing “site-specific” about the new Site Specific Objectives. However, that is not a problem with the Recalculation Procedure itself, but rather with how to interpret the results.
There are four target species of concern in the LA River (three are state-designated rare species and one is designated as threatened by the federal government). However, none of the data sets involves any of these species, so deciding the recalculated standards (which are up to 1,351% more lenient at high hardness values, and about 150–200% more lenient at typical LA River hardness values) involves major extrapolation. The Recalculation Study designated the species represented in the data sets that were most closely related to the four target species as “surrogate” species, noted that all four of these species demonstrated significant adverse effects from lead at levels above the recalculated standards, and assumes that the target species respond to lead in the same manner. This is a concern because 3 of the 4 surrogate species are not even in the same genus as the target species, and one surrogate is no more closely related than the same Order as the target (that’s as distantly related biologically as humans and lemurs). Yet very little follow-up monitoring is required to verify whether the numerous assumptions hold up in the conditions in the LA River, or whether the target species are more sensitive to lead (all target species are rare, versus none of the surrogates).
In contrast to the Recalculation Procedure, the Water Effect Ratio (WER) Procedures we are also challenging are truly site specific. Our Petition to the Superior Court describes WERs and the LA River WERs for copper in detail, so I will not go into excruciating detail here. But there are several key points to understand about WERs in general and the LA copper WERs in particular. The equations setting acute and chronic copper standards involve numerous terms resulting in a number (with units typically in mg/L) representing the maximum “safe” level of pollution (the Objective), and for impaired waterbodies like the LA River, another set of equations similar in form describes the maximum contribution of each individual source to the overall “safe” levels known as the Total Maximum Daily Load (TMDL). The copper WERs are simply an experimentally derived unit-less ratio between the toxicity of additional copper added to a sample of water from the LA River and containing a population of water fleas to the toxicity of the same amount of copper added to a laboratory control sample containing the same number of individuals from the same species of water flea.
By regulation, WERs are set at a default value of 1.0 so there is no effect on the overall standards. But the WER term is a coefficient applied to all the terms in any of the equations, so adjusting the WER from its default value of 1.0 can have huge consequences for the numerical standards. WERs are supposed to accurately reflect the dynamic site specific (bio)chemistry of waterbodies, and so to set an overall site specific objective that in theory is exactly as equally protective as the national standard, the WER term should be set at the lowest value the WER achieves over the course of a hydrological cycle, a value known as the “critical condition.”
Failure to set the WER term at anything other than the critical condition results in a less protective standard.
The regulations implementing the Clean Water Act allow for standards to be weakened in some instances, but the same regulations contain an absolute prohibition on actions that further degrade the quality of a waterbody that already contains pollution in excess of the standards. This regulatory prohibition is part of the “Anti-degradation” standard. We will discuss this issue more next time, and why it is so important in this case.
The “Resident Species Procedures” are not at issue in our lawsuit, so I won’t go into detail here, but like WERs and Recalculations, the basic idea is that the Procedure results in a new water quality standard that is in theory equally protective but reflects the unique environmental conditions of the local waterbody. EPA describes the purpose as “account[ing] for differences in residential species sensitivity and differences in the biological availability and/or toxicity of a material due to physical and/or chemical characteristics of site water.” If applied to the LA River, the Resident Species Procedure would basically have asked if there is evidence that organisms living in the LA River have evolved a tolerance for copper and lead that similar organisms in less polluted environments have not. The Resident Species Procedure is expensive and time consuming, and rarely used. However, if it had been used in the context of the LA River SSOs, it might have answered many of the questions regarding surrogate and target species left open by the Lead Recalculation Study.
So now that you have a better idea what a “Site Specific Water Quality Objective” is, next time we will start to explain why we think the SSOs for copper and lead for the LA River and its tributaries should be rescinded.
 Although, as the Recalculation Procedure study recognizes, the upshot of adding the new data sets to the existing ones is that the LA River Recalculation Procedure study represents a de facto recalculation of national aquatic lead standards. Also (but not disclosed in the study itself), the addition of all new EPA approved data sets to existing data sets produces a recalculated standards that is higher (i.e., less protective) than if fewer data sets were used, thanks to certain probability and statistics rules that are relevant to the Recalculation Procedure.