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Kentucky Division of Water Initiates its Triennial Review of Water Quality Standards


In June 2012, the Kentucky Division of Water (DOW) initiated its Triennial Review of Kentucky Water Quality Standards required by Section 303(c) of the Clean Water Act by advising the regulated community of its planned changes to the Water Quality Standards.  DOW is considering making several revisions to its surface water standards and is also proposing to establish new Outstanding State Resource Water (OSRW) uses for various surface waters in the state.  DOW plans to file the proposed regulations with the Legislative Research Commission in early July.

One important change/clarification that DOW is considering relates to the narrative surface water standard for nutrients at 401 KAR 10:031 Section 1.  The revisions to the narrative nutrient standard would be proposed to clarify DOW’s longstanding interpretation and application of the standard.  In particular, DOW is expected to clarify the standard through an expanded definition of the term “eutrophication” and by specifying in the narrative standard that nutrients shall not be elevated in a surface water to a level that results in adverse impacts to the aquatic community due to excessive eutrophication (e.g., a eutrophication problem).  The proposed change is in response to a recent Hearing Officer ruling that disagreed with DOW’s interpretation of the current standard and required limits on nutrients in wastewater discharges even where eutrophication problems did not exist in the surface water as long as there was evidence that a eutrophication process was occurring.  As DOW has noted, eutrophication is a process that occurs to some degree in all surface waters, but the existence of a eutrophication process does not establish that the stream is impaired for nutrients or that nutrient levels are adversely impacting the aquatic community.

As part of the Triennial Review, DOW is also expected to clarify the dissolved oxygen standard that applies to the main stem of the Ohio River.  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 application of the dissolved oxygen standard by EPA.  The clarification would specify that the dissolved oxygen standard is an instream standard that is achieved after mixing with the receiving water.

The proposed regulation would also identify additional stream segments for which an OSRW use would be established.  OSRWs are potentially subject to additional use protection under 401 KAR 10:031 Section 8.  Surface waters may be considered for inclusion in the OSRW use category where DOW determines the waters are of exceptional aesthetic or ecological value or are a part of unique geological or historical area recognized by state or federal designation.  OSRWs may also be established where the surface water is a component part of an undisturbed or relatively undisturbed watershed that can provide basic scientific data and it possesses outstanding water quality characteristics.  It is not mandatory for the state to make OSRW designations and there is currently some amount of judgment involved in the application of the permissible considerations.  Because an OSRW designation can restrict or essentially prohibit certain land uses that would adversely affect the stream segment, where such designations are proposed for private property it is imperative that the property owner have an opportunity to review and evaluate the basis for the designation. 

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

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