Engineering Design Manual - Loudoun Water

Chapter 8: Community Wastewater Systems
T. Standards
To 9 VAC 25-790-460 add the following:
For wastewater flows of less than 0.02 mgd, the required treatment system is septic
tanks/recirculating sand filters (RSF) with subsurface land disposal. For flows from 0.02
– 0.04 mgd, RSF and subsurface disposal shall be compared on a cost-of-service basis to
other technologies. For flows greater than 0.04 mgd the most cost effective technology
shall be provided.
U. Treatment Works Details
To 9 VAC 25-790-470 add the following:
B. Instrumentation
1. All influent and effluent flow meters shall be provided with indicating, totalizing
and digital recording equipment. Meters shall be Badger M3000 electromagnetic flow
meters with appropriate appurtenances as required.
E. Essential Facilities
5. Loudoun Water owns and operates a regional laboratory and as such, the
minimum laboratory space of 400 square feet shall not be required unless specifically
required by Loudoun Water in the Basis of Design. Note that sufficient work space must
still be provided for daily operations tests.
F. Odor Control
1. Odor control provisions shall be required.
G. Treatment facilities shall provide the following standard equipment:
Safety equipment and signs, including appropriate arc flash protective
equipment
Maintenance equipment
Laboratory equipment and supplies
Confined entry equipment
Doors shall have closers and wall mounted hook doorstops. Keys shall have
replaceable cores and be matched using the Loudoun Water standard.
Potable water system for wash down facilities, lavatory and laboratory
Wash down facilities for each major unit process. Major unit processes will be
identified as such by Loudoun Water during the review of the “Basis of
Engineering Design Manual
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