Letter from Loudoun Water dated Decmber 21, 2011:

Dear Resident:

On December 5th, Loudoun Water released the results of its investigation of an event that occurred on August 9, 2011, when elevated turbidity was experienced in a portion of the system.  The results of the investigation may be found by clicking here.

As part of the release of the results, Loudoun Water announced it was awaiting confirmation of its conclusions from the Virginia Department of Health (VDH) that Well F remains an acceptable source for drinking water in the community.  Loudoun Water also stated it was awaiting approval of its response plan it crafted to help try to eliminate elevated turbidity events from happening in the future.

Loudoun Water is pleased to announce it has received from VDH a formal confirmation of the results of Loudoun Water’s investigation stating that 1) Well F is an acceptable water source that can be placed back into service following the implementation of recommendations submitted in the response plan; and 2) there is no significant bacteriological water quality problem associated with the observed turbidity since 4-log inactivation is provided.  The letter from VDH confirming the results of the investigation be found by clicking here.

In Loudoun Water’s response plan, we stated we would: 1) install, in consultation with the Virginia Department of Health, an automatic flow control valve on the raw water main at the water treatment plant – this will eliminate the “hard start” conditions and allow us to prevent over-pumping; 2) bring Well F back online at a production rate of 75 gallons per minute (gpm) for a minimum of three months. After that period of time, the pumping rate may be increased to 100 gpm to meet demands; and 3) monitor water levels, flow rates and turbidity continuously for the next 12 months.

In addition to the recommendations, VDH is requiring weekly MPN testing of the raw water samples from Well F.  Loudoun Water has been conducting weekly MPN testing since the beginning of 2011.  VDH also requested that the turbidity monitoring system we have installed be able to automatically alarm and shut down Well F during a high turbidity event.  Loudoun Water will take the necessary measures to meet this request.

The results of the Loudoun Water investigation and VDH’s review of the findings can be found on the Raspberry Falls web page of Loudoun Water’s website, www.loudounwater.org.


Mike McGill
Manager of Community Relations

Loudoun Water

44865 Loudoun Water Way
Ashburn, Virginia 20146
O) 571-291-7969
C) 443-995-9144