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Kentucky Division of Water Files Proposed Regulations for its Triennial Review of Water Quality Standards


As reported in the May/June 2012 Bingham Greenebaum Doll Environmental Letter, the Kentucky Division of Water (DOW) initiated its Triennial Review of water quality standards required by Section 303(c) of the Clean Water Act earlier this summer when it advised the regulated community of its planned changes to the water quality standards.  On August 15, 2012, DOW formally filed proposed amended water quality regulations with the Legislative Research Commission relating to its Triennial Review.  Amendments have been proposed to 401 KAR 10:001 (Definitions); 401 KAR 10:026 (Designation of Uses); 401 KAR 10:030 (Antidegradation Policy Implementation); and 401 KAR 10:031 (Surface Water Standards).  Although the number of amendments that have been proposed is limited, there are several very important regulatory changes and clarifications.

One of the most important changes/clarifications that DOW has proposed relates to the narrative surface water standard for nutrients at 401 KAR 10:031 Section 1.  The revisions to the narrative nutrient standard are intended to clarify DOW’s longstanding interpretation and application of the standard.  401 KAR 10:031 Section 1 currently provides that in “surface waters where eutrophication problems may exist, [nutrients] shall be limited in accordance with:  (1) the scope of the problem; (2) the geography of the affected area; and (3) relative contributions from existing and proposed sources.”

The current regulation has been interpreted as requiring limits on phosphorus and/or nitrogen in wastewater discharges where the discharges would cause or contribute to a eutrophication problem in the waterbody.  The proposed amendments to the nutrient criterion provide “nutrients shall not be elevated in a surface water to a level that results in eutrophication.”  The definition of “eutrophication” is being clarified in 401 KAR 10:001 Section 1(30) as follows:

“Eutrophication” means the enrichment of a surface water with nutrients nitrogen and phosphorus resulting in adverse effects on water chemistry and the indigenous aquatic community.  Resulting adverse effects on water chemistry manifest by daily dissolved oxygen supersaturation followed by low dissolved oxygen concentrations and diurnal increase in pH...

The definition also includes a list of adverse effects on the aquatic community that could result from eutrophication. The proposed definition of eutrophication requires both adverse effects on water chemistry and the indigenous aquatic community.  As with other water quality standards, a discharge would need to cause the eutrophication problem or contribute to an existing eutrophication problem before limits on nutrients in the discharge are required.  It is likely that DOW will have the opportunity to clarify its interpretation of the proposed standard in its Statement of Consideration on comments that are received during the public comment period.

DOW is also clarifying the dissolved oxygen standard that applies to the main stem of the Ohio River at 401 KAR 10:031 Section 9(2).  Specifically, DOW is clarifying that the dissolved oxygen standards set forth in the regulation are “instream” concentrations and do not apply at the end-of-pipe.  This clarification is intended to ensure that the standard is construed consistent with the Ohio River Valley Water Sanitation Compact’s (ORSANCO) dissolved oxygen standard and the longstanding application of the dissolved oxygen standard by EPA and DOW.

DOW is also proposing to delete the acute criterion for selenium at 401 KAR 10:031 Section 3.  The chronic criterion for selenium for protection of warm water aquatic habitat is not proposed for amendment or deletion.  DOW is proposing to delete the acute standard because it is outdated and not based upon sound science.  In fact, EPA has acknowledged that the acute aquatic life criterion for selenium is not scientifically supported.  See 69 Fed. Reg. 75541, 75544 (Dec. 17, 2004).  More recent acute toxicity testing indicates that the acute criterion should be substantially increased (more than one magnitude) from the current criterion.  EPA will reportedly publish a draft recommended water quality criterion for selenium in early 2013 that will take into consideration the latest scientific data and will likely be based upon a fish ingestion standard.  A translator would be needed to convert the ingestion standard to a water column concentration.  DOW’s proposed amendment is significant for any entity discharging wastewater containing selenium where a mixing zone may be available as those are situations where the current acute criterion could be controlling.

DOW is also proposing additional stream segments for which an Outstanding State Resource Water (OSRW) use designation would be established.  There are 27 new OSRW designations proposed, of which 11 are stream segments that qualify for automatic inclusion as OSRWs because they serve as habitat for federally-listed threatened or endangered species.  DOW has also proposed to add 16 streams or stream segments as exceptional waters under 401 KAR 10:030.

With respect to the standards for designation of stream segments as OSRWs, DOW has proposed to delete the automatic inclusion criteria for streams within  a dedicated nature preserve or that are published in the Registry of Natural Areas in accordance with 400 KAR 2:080.  DOW has proposed to add surface waters that are a “natural” area recognized by state or federal designation as subject to permissive consideration as an OSRW.  The state explained this will ensure that waterbodies designated as OSRWs in areas of unique geological, natural, or historical significance will in fact have exceptional water quality and/or habitat.  Under the current regulation, streams within nature preserves would be subject to automatic OSRW designation even if the waterbody does not possess excellent water quality.

A hearing on the proposed Triennial Review amendments is scheduled for September 27, 2012.  The public comment period on the proposal will remain open through October 1, 2012.

To view a complete PDF of the July/August 2012 issue of the Environmental Letter, click HERE.

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