PROJ00283

• Contract/PO #: FS0009X
• Contractor Name: Swink, Town of
• Contract Type: Loan
• Water District: 0
• County: Otero
• Loan Projects - Doc Type: Feasibility Study

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4.4 DESIGN CRITERIA AND STANDARDS

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4.4.1 Distribution Mains and Appurtenance. The potable water distribution
system as proposed for construction at the earliest possible date is shown on
Plate II. The system consists of 8-inch and 6-inch mains with some 4-inch and
2-inch connections into the existing soft water system. The size of pipe, valve
locations, and hydrant locations are shown on Plate II. Distribution mains are
sized to deliver fire flows and are integrated with the existing mains to the
maximum extent possible. When construction is completed as shown on Plate II,
fire flows of approximately 1000 gallons per minute can be achieved in the resi-
dential areas that are currently developed. Along the new mains and in the Town's
business district, fire flows of 1500 gallons per minute can be delivered.

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Fire hydrants will be spaced to provide an average area per hydrant of approxi~
mately 150,000 square feet. All materials used in the distribution system will
be conventional water works materials as approved and recommended for use in public
water systems ,by the Colorado Department of Health, the U.S. Public Health Service,
and the American Water Works Association. These materials are readily available
from numerous sources. Delays due to manufacture, fabrication, and transportation
are not anticipated.

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The water supply well pumps will be connected to the water treatment facilities.
Storage tank levels ~ill "floatll on the distribution system and "water hammer"
is not expected to be a problem. All bends, tees, crosses, valves and hydrants,
and plugs shall be provided with adequate thrust blocking. The distribution mains
and appurtenances will be flushed, sterlized and pressure tested prior to being
placed in service.

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The non-potable water system as proposed for construction at the earliest possible
date is shown on Plate III. The system consists of 6-inch and 4-inch feeder mains
connected into the existing IIhardll water mains. Pressure reducing-pressure
modulating valves will be installed on the well pump discharge lines to prevent
excessive pressure fluctuations on the mains. S~me additional selective re-
placement of existing cast iron mains may be required if low flows persist after
installation of the feeder mains.

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The hydraulic characteristics of the distribution system including the sizing
of mains and the delivery of required fire flows is based on a Williams and Hazen
Formula C value of 130. The pipe materials to be used will have a minimum C value
of 130 and will meet or exceed the design criteria used for flow analysis. Con-
sideration of alternate materials with comparable flow characteristics will be
given during the design and competitive bidding processes.

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4.4.2 Storage. Storage facilities as proposed for construction at the earliest
possible date are shown on Plate II. The location was selected to give balance
to the system and provide for future expansion. The preliminary location of
the storage tank is still somewhat flexible and several alternate sites may be
utilized within the general area without causing appreciable change to the hydraulic
characteristics of the system. Average pressures on the system will be approxi-
mately 45 psi. The new storage tank can be either the conventional "leg" type
tank (similar to the existing tank) or the new pedestal sphereoid type. The newer
sphereoid type offers certain advantages such as a slight reduction in long-term
maintenance costs (painting) and a more aesthetic appearance; however, initial
construction cost is usually higher.

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4.4.3 Wells and Well Houses. Wells and equipment must be adequately protected
from severe weather conditions and vandalism. The well houses on wells No. 3 and
4 are considered inadequate and will be replaced. New flow meters will be installed

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