Karst Hydrogeologic Implications of the GUDI Determination for Raspberry Fall's - E. Calvin Alexander, Jr. Roy A. Jameson

12/14/10
Letter sent to:  Mr. Frank Wolf – Congressman of Virginia

Mr. Mark Warner - Senator of Virginia

Mr. Jim Webb - Senator of Virginia

Mr. Bob McDonnell – Governor of Virginia

Mr. Ken Cuccinelli – Attorney General of Virginia

Mr. William Bolling – Lieutenant Governor of Virginia

Ms. Jill Vogel – Virginia State Senator

Dr. Wesley Kleene – Director VDH/ODW

Dr. Karen Remley – State Health Commisioner

Loudoun County Board of Supervisors:

Mr. Scott York, Chairman

Ms Susan Klimek Buckley, Vice Chairman

Mr. Jim Burton

Ms. Lori Waters

Ms. Sally Kurtz

Mr. Stevens Miller

Ms. Kelly Burk

Ms Andrea McGemsey

Mr. Eugene Delgaudio

Mr. Tim Hemstreet – Loudoun County Administrator

Mr. Charles Yudd – Assistant to the County Administrator

Mr. Terry Wharton – Director of Building and Development

Loudoun Water Board of Directors:

Mr. Edward Burrell

Mr. Charles Harris

Mr. Dimitri Kesari

Mr. Mark Koblos

Mr. Leonard Mitchell

Ms. Patti Psaris

Mr. Johnny Rocca

Ms. Tanja Thompson

Leesburg Town Council:

Mayor Kristen Unstattd

Vice Mayor Kevin Wright

Mr. David Butler

Mr. Tomas Dunn II

Ms. Katie Sheldon Hammler

Mr. Fernando Martinez

Mr. Kenneth Reid

Ms. Jeanette Irby –Leesburg Town Attorney

Mr. John Wells – Leesburg Town Manager

In our professional opinion, the continued use of any of the community wells at Raspberry Falls as drinking water supplies constitutes significant, unacceptable health risks to the people drinking the water.  The November 2010 Virginia Department of Health (VDH) classification of the Raspberry Falls water supply well PW-1 as Groundwater under the Direct Influence of Surface Water (GUDI) is correct, overdue, and clear evidence that any water supply well in that karst aquifer is dangerous.  The wells tap into a pre-existing karst network with conduits that transport contaminants rapidly into the wells.  The main contaminants considered by Loudoun Water and the Virginia Department of Health to date are Total Coliform and E. coli bacteria, but other contaminants, such as spills of hazardous waste and application of horticulture nutrients and chemicals at the surface pose a serious long-term risk at Raspberry Falls and elsewhere within the karst drainage of the Limestone Overlay District (LOD).

The water supply well PW-1 was earlier miss-classified as not GUDI by the VDH based on inaccurate and incomplete information. The mistaken classification ignored the fact that the Raspberry Falls development was constructed on a sinkhole plain with “Potential Conduits to Groundwater”. The “No” response to question 1C on the GUDI Determination Review Sheet (are sinkholes present?) is incorrect.  The correct “Yes” answer is that sinkholes are present and all wells in the LOD aquifer are potentially GUDI.  The developers’ filling of many sinkholes and extensive modification of the land surface partly obscured the nature of the water supply aquifer - but did not change the health danger presented by use of that karst aquifer for public water supplies.   

Continued use of the wells as previously operated at PW-1, and as continues at PW-2, is not a prudent public health practice.  All of the wells are liable to be declared GUDI over time. The absence of evidence of GUDI is not evidence that GUDI is absent. The use of the community wells as potable water supplies should be discontinued.

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1.  Department of Geology & Geophysics, University of Minnesota. 310 Pillsbury Dr. SE, Minneapolis, MN 55455. (612) 624-3517, alexa001@umn.edu.

2. 1808 Gardenspring Dr., Blacksburg, VA, 24060. (540) 552-0637, rjcb19@comcast.net. 

The documented major and highly variable bacterial contamination of the raw water is being addressed by heavy chlorination.  Heavy chlorination leads to adverse health effects in susceptible individuals, who develop rashes and breathing problems from showering and gastrointestinal problems from drinking the water.  Heavy chlorination also leads to problems with pithole corrosion of copper pipes, and has led to significant leaks in Raspberry Falls homeowner’s basements and resulted in considerable costs.  Appropriate alternative potable water supplies should be provided immediately to Raspberry Falls residents.

If the wells are to be used as a source for potable water---to which we are firmly opposed---then a state-of-the-art Water Treatment Plant (WTP) should be installed.  That WTP should be capable of removing not just bacteria, but a wide range of chemical and biological contaminants.  That WTP should not create additional problems such as those caused by over-chlorination.

The quantity of water supplied by the wells has been judged insufficient by Raspberry Falls residents’ needs, particularly during summer months.  Signs posted at fire hydrants in the subdivision warn firefighters of limitations on the amount of water that can be pumped in the event of fire.  Perhaps installation of a complete WTP would open up alternative sources of surface water that would partly ameliorate the existing water-supply limitations imposed by extensive withdrawls of karst aquifer water.

Loudoun Water should move forward with alternate plans to supply potable water to Raspberry Falls, and discontinue the policy of drilling additional ground-water supply wells.  Additional pumping from existing or new wells will only exacerbate the problems associated with the GUDI nature of the karst aquifer. The December 9, 2010 Resolution by the Loudoun Water Board directs Loudoun Water staff to evaluate options required by Commonwealth laws (12VAC-590-420 of the Waterworks Regulations) and by implication Federal regulations (Groundwater Rule, and Surface Water Treatment requirements) such that they “are consistent with the Loudoun County Revised General Plan.”

Selma Estates north of Raspberry Falls also uses karst water, and is part of the same aquifer.  It is clear that the problems posed by the GUDI determination for well PW-1 are problems that need to be addressed for the entire Limestone Overlay District.  A complete, long-term karst hydrogeologic evaluation of the entire Limestone Overlay District is needed.

We strongly encourage Loudoun Water (and the Virginia Department of Public Health) to proceed with dye tracing, not just at Raspberry Falls, but elsewhere within the Limestone Overlay District (LOD).  Development of Loudoun County rural areas is expected to continue. The Limestone Overlay district is extensive.   The water contamination problems will occur at new locations.  An accurate and detailed understanding of the subsurface flow paths is essential for long-term planning, particularly in the event of spills of hazardous substances, which could flow rapidly into water-supply wells, or through the subsurface to emerge at springs before flowing in small streams eastward into the Potomac River.  State agencies need to be mobilized to coordinate dye tracing.  State agencies need to develop long-term plans to revise ground-water procedures and regulatory policies so that they more adequately take into account the realities of flow in karst aquifers.  Long-term plans should include monitoring of springs and extensive water sampling of springs to determine their hydrologic behavior, including response to major recharge events.