The project is a Water System Master Plan for the City of Douglas and
the adjacent areas served by the City of Douglas. There are currently
2,275 taps within the corporate limits of the City of Douglas and
approximately 75 outside the city limits. A population of 5,800 is
served. These areas include users along the Little Box Elder Spring
transmission line, Sheep Mountain Well transmission line, and the
Ridgewater Estates Improvement and Service District. The city currently
has three sources of potable water: 1) the Little Box Elder Spring, 2)
the Water Treatment Plant located along the North Platte River, and 3)
the Sheep Mountain Well. The Master Plan would evaluate the existing
transmission and distribution system and examine the ability of the
sources in the system to meet the current demands and future demands in
the anticipated areas of growth in Douglas. Hydraulic modeling would
isolate the cause for low water pressure problems in two areas of the
city, Riverbend Subdivision and Frontier Village. Potential system
modifications would be considered to meet current and projected growth
areas which are experiencing inadequate system pressures. Preliminary
designs would be evaluated to determine potential solutions and costs
for remedying transmission, distribution and zoning problems.
In addition to the hydraulic modeling and transmission and distribution
system evaluation, treatment of the potable water sources would be
evaluated. The water treatment plant was constructed in the early
1980's. Treatment and disinfection requirements have become more strict
since that time by amendments to the Safe Drinking Water Act.
Specifically in question is the chlorine contact time (CT) and chlorine
residual at the water treatment plant. Additionally, the Disinfection
Rule will require the city to meet CT requirements for the Sheep
Mountain Well and the Little Box Elder Spring. There are currently over
30 domestic taps ahead of the point of chlorination on the Spring
Transmission Line. Access to the spring is limited and will need to be
improved if the point of chlorination is moved to the spring house.
The City of Douglas has experienced steady growth since the late 1980's.
Additional potable water sources have been added to meet the increasing
demands in the system. However, the entire transmission, distribution
and storage system has not been evaluated or updated.
The City of Douglas' water transmission and distribution system contains
cast iron pipelines which were constructed in the 1940's. These
portions of the system are undersized and maintenance intensive.
Portions of the distribution system do not meet the requirements for
minimum operating pressure as required by the Wyoming Department of
Environmental Quality. This poses a potential health risk in terms of
cross connections and the potentially disastrous effects of restricted
The water treatment plant and the Sheep Mountain well have been added to
the system over the years. As they were added to the system, the
impacts of each source on the entire system was never thoroughly
evaluated. Currently there are several hydraulic limitations and
"bottlenecks" in the transmission and distribution system caused by the
three sources competing to supply the demands. All of the sources enter
the system along the northwest edge of the city; consequently, the tank
on this side of town is always full while the tank serving the greater
area on the east side of the city is commonly less than half full.
The water treatment plant would not currently meet the EPA disinfection
requirements if it was operated at full capacity. Additionally, a
thorough evaluation of the treatment train and techniques needs to be
performed to verify compliance with all of the rules and regulations in
the Safe Drinking Water Act amendments.
Sear-Brown has been hired to complete a Level II study. The contract
will be completed in 1998.
RECOMMENDED LEGISLATIVE ACTION:
No legislative action is needed at this time.