Audit of Major Commercial & Irrigation Water Accounts

• Project Type: General OWC
• Applicant: Town of Castle Rock
• Project Name: Commercial & Irrigation Water Audit
• Title: Audit of Major Commerical and Irrigation Water Accounts
• Date: 6/29/2006
• County: Douglas
• Water Conservation - Doc Type: Final Report

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Audits of Major Commercial and Irrigation Water Accounts
Town of Castle Rock

Western Mobile Pre-Mix (account 4457)
Western Mobile Pre-Mix, shown in Attachment 3, operates a year-round concrete batch
plant on Gilbert Street in south-central Castle Rock. Town water at this facility is chiefly
used as make-up water for the batches of concrete, although a minor amount of water is
used to clean the cement trucks, provide for dust suppression, maintain temperature
control of the aggregate during the summer months, and support a minor amount of
indoor water use (a sink and a toilet).

All of the various water uses at this facility are directly tied to local construction activity
and to a lesser extent the available supply of cement - locally and nationally. Because of
the dependency of the facility on construction activity, the water usage at Western Premix
demonstrates seasonal fluctuations over the summer. These fluctuations are not related
to irrigation practices, however, since the facility maintains no irrigatible plantings.
Attachment 4 presents the monthly water use at this facility in 2004 and 2005.

The facility does employ a modest amount of water conservation based chiefly on the use
of a truck wash pad that collects and recirculates truck wash water for dust control. Dust
control is maintained through the use of a single Rainbird sprinkler mounted near the
facility entrance. It is operated manually, as needed. The facility, which is over 30 years
old, also uses water for boiler make up water.

There are times when the existing 2-inch tap does not meet peak water demands of the
facility. For this reason, Western Pre Mix has installed a 6,000-gallon tank on site to
assist with peak demand requirements.

Future water savings are planned for the facility, based on discussion with Eric, the plant
manager. The facility is looking to upgrade its batch plant and related water handling
facilities within 2 years. The new plant would look to batch with recycled water.

Alternatives and Recommendations
Western Pre-Mix is not the type of facility that lends itself readily to improved water use
without substantial process plumbing changes. Concrete requires a certain volume of
make-up water to be of appropriate strength and consistency. As long as the local demand
for concrete exists, the water use of this facility will continue to fluctuate based on the
demand for concrete.

One option that the Town has for this and other like facilities in Town is to provide
untreated or reclaimed water for their use. Although this option is not readily
implemented at this time, it may become feasible at some point in the future.

Finally, it will be difficult to employ a water budget approach to this commercial
enterprise, since its water use is based on concrete demand. It may be worthwhile to
continue to monitor this facility's water use into the future to better understand the range

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