Dowingtown Area Regional Authority (“DARA”) filed a December 28th Notice of Appeal (“Appeal”) before the Pennsylvania Environmental Hearing Board challenging a Pennsylvania Department of Environmental Protection (“DEP”) direction to conduct a biotic ligand model (“BLM”) based study for copper.
DARA states it had requested the opportunity to use a site-specific approach using Water Effect Ratio (“WER”).
DARA is a joint sewer authority between the Borough of Downingtown, the Townships East Caln, Uwchlan and West Whiteland. It owns and operates a water pollution control plant (“Plant”) in Chester County, Pennsylvania.
DARA is said to have participated in a WER group copper study.
The WER method compares the bioavailability of a pollutant in both receiving and laboratory water. Toxicity tests are conducted for at least two species. The pollutant is measured at LC50 using the local water source. The chemical hardness of laboratory toxicity testing water is compared with the site water. The site water and laboratory LC50 are used to adjust the acute or chronic criterion for site specific values.
The DEP submitted the WER study in 1998. It is stated to have confirmed that copper was present in the Plant’s effluent. The Plant’s effluent was stated to be in a non-toxic form and that it had additional copper binding capacity. As a result, DARA argues that DEP proposed to amend the DARA Plant’s 2018 discharge permit by incorporating the results of a WER into the calculation of the water quality based effluent limit for copper.
According to DEP, a permit issued in 1998 required an updated site-specific copper criteria analysis and other actions. DEP has stated that it amended the Pennsylvania rules in 2020 to reflect the following change.
(c) Scientific studies shall follow the Water Quality Standards Handbook 1994 (EPA 1994), as amended. This includes: ‘Guidance for the Determination & Use of Water-Effect Ratios of Metals” (February 1994) and ‘Methodology to Derive Ambient Water Quality Criterias for the Protection of Human Health’’ (2000). Other guidance approved and scientifically supported by the Department may be used. The biotic-ligand model (BLM), shall be used for the development of new or revised site-specific criteria to determine copper in freshwater systems. (emphasis added)
DARA believes that the new rule is more restrictive than the previous rule in copper matters and allows for BLM to adjust copper’s site-specific criteria. The rule also allows WER to be used to make other metals.
DARA believes in its appeal
- The application of the BLM to site specific copper criteria is severely flawed and not scientifically defensible. It results in excessively restrictive site specific criteria for copper.
- DEP acted arbitrarily, abused its discretion and erred as a matter of law in applying the amended section 93.8(d) to DARA’s current permit.
Download a copy the appeal Here.