Client project details

Loudoun Water (Raspberry Falls)

The Project

One year after the repairs completed by EGGI on Production Well F at the Raspberry Falls Community ….. Well F continues to provide an excellent supply of water to the Raspberry Falls Community… both in quality and quantity. The success of EGGI’s approach to well maintenance and management has saved the Loudoun Water Utility hundreds of thousands of dollars in water source replacement costs.

On August 9, 2011, elevated turbidity was observed in a portion of the system during routine monitoring.  Following the incident, Loudoun Water enlisted Emery & Garrett Groundwater, Inc., a company with a significant, positive track record of work in Loudoun County, to conduct an investigation into the incident.  In consultation with VDH, Emery & Garrett and Loudoun Water then conducted a series of pumping tests and water quality tests to further assess turbidity to determine the cause of the elevated turbidity.

Status/Results:

Most importantly, the investigation confirmed that Well F is an acceptable water source and should not experience high turbidity if the pumping rate of water is controlled.  It revealed that the event was caused by unforeseen hydraulic transients in the raw water main.  These transients – which, in this case, were rapid fluctuations in flow and pressure – allowed the well pump to operate at higher discharge rates than it was designed to maintain.

The investigation also found that when Well F began pumping, it was immediately, but briefly, pumping at higher than anticipated rates due to low backpressure in the pipeline.  This was referred to by Emery & Garrett as a “hard start”.  Water levels in Well F were also found to rapidly fluctuate by one foot or more during some pumping intervals.  These fluctuations confirmed that unstable (and variable) pumping rates were occurring, agitating water within with well casing, and increasing the turbidity in the well.

Based on the results of the investigation, Loudoun Water submitted a response plan to VDH to address the issues and return Well F into service.

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Following the incident, Loudoun Water enlisted Emery & Garrett Groundwater, Inc., a company with a significant, positive track record of work in Loudoun County, to conduct an investigation into the incident.

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P.O. Box 1578
56 Main Street
Meredith, NH 03253
T: (603) 279-4425
F: (603) 279-8717
eggi@eggi.com

“Data and research provide the underpinning for sound local water management decision-making that advances the well-being of the nation’s citizens, economy, and environment.”

- National Ground Water Association