ACWWA 2007 WCPlan

• Project Type: Water Conservation Plan
• Applicant: Arber Water, WasteWater & Reuse Engineers
• Title: Arapahoe County Water and Wastewater Authority Water Conservation Plan
• Date: 11/1/2006
• County: Arapahoe
• Water Conservation - Doc Type: Complete Plan

Water Conservation Plan

1.2.1 Cherry Creek Alluvium

Water from the Cherry Creel( Alluvium currently meets all primary drinl(ing water standards,
however there are concerns with water quality and aesthetics. The alluvial wells used by
ACWW A are under the influence of wastewater treatment plant effluent from Stonegate Village
Metropolitan District (Stonegate), Parl(er Water and Sanitation District (Parl(er), and Pinery
Water and Sanitation District (the Pinery), all of which discharge upstream of the wells.
Additionally, after the completion of the new Joint Water Purification Project (JWPP) and the
Lone Tree Creel( Water Reuse Facility (L TCWRF) Expansion, some of the L TCWRF effluent
will be discharged upstream of the alluvial wells. See Section 3.1.1 for more information on
these projects. Currently, under average conditions the maximum percentage of effluent in the
alluvium is 56% which is expected to increase to 80% in the future. The influence of wastewater
effluent on Cherry Creel( is expected to increase in the future as discharge from Stonegate,
Parl(er and Pinery increase due to growth, and as effluent from L TCWRF is returned to the
alluvium. In addition to wastewater effluent, the alluvium is heavily influenced by urban runoff.

1.2.2 Arapahoe Aquifer

The Arapahoe Aquifer provides water of very good quality that meets all primary drinl(ing water
standards. The water is consistently cool and has low total hardness (approximately 50 mg/L as
CaC03) and low total dissolved solids (TDS) (150 mg/L). At times, iron has been detected in
Arapahoe Aquifer water at concentrations above the secondary standard of 0.3 mg/L which can
cause aesthetic problems. Even though the secondary standard for iron can be exceeded with the
Arapahoe Aquifer water, the water poses no health effects. (WWE 2002)

1.2.3 Laramie-Fox Hills Aquifer

The LFH Aquifer has higher temperature (900 to 1000 F) and a higher TDS (500 mg/L) than the
Arapahoe Aquifer. The LFH water also has a strong hydrogen sulfide smell, with concentrations
above secondary standards. Because of the high temperature and strong odor, the LFH Aquifer is
the least desirable water source for ACWW A. In addition, the LFH Aquifer has occasionally
exceeded National Secondary Drinl(ing Water Regulations for fluoride in the ACWW A area.

1.2.4 Dawson and Denver Aquifers

Both the Dawson and Denver Aquifers have low production rates (approximately 50 gpm) and
generally poorer water quality than the Arapahoe Aquifer. Because of this, these aquifers are the
lowest priority for development.

1.3 SYSTEM LIMITATIONS

In order to determine areas of the Authority's operation that could be improved, the next part of
this plan examines the system's limitations. Worl(sheet 1-2 (Appendix A) provides a summary of
basic system conditions and limitations.

November 2006

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Richard P. Arber Associates, Inc.