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3.2 CHAPTER THREE

commissions. In addition, there will be state and federal authorities having jurisdiction
over water supply public health and environmental issues. Close coordination and com-
munication with these agencies during the preliminary design phase is essential, as the
plant design will eventually be reviewed and approved by these agencies.
Most regulatory agencies have design standards or guidelines that should be reviewed
to identify any potential impacts to the project. As part of this review, agency permits re-
quired for the project should be identified. Permits may be required for a number of plant
design issues that could affect project implementation, such as site approval, stormwater
management, plant discharges to receiving streams, construction in waterways, environ-
mental impacts, and water rights.
Although it may not be required, it is often beneficial to submit copies of preliminary
engineering documents to regulatory agencies for review and comment, to avoid major
changes during final design.

Plant Siting Analysis

Selection of potential sites for a new water treatment plant must take into consideration
a number of factors. Some of the principal ones are
• Proximity of plant site to the source water and to customers being served
• Consideration of water transmission requirements to interconnect the plant to the source
water and the water distribution system
• Proximity of plant site to ultimate treatment waste disposal location
• Environmental and land use concerns
• Subsurface and geotechnical considerations
• Land availability, cost, and zoning
• Storage requirements at plant site for raw water supply
• Compatibility with surrounding existing and planned developments
• Potential for flooding and stormwater handling requirements
• Availability of utilities (power, natural gas, sewer, telephone)
• Site topography and accessibility
• Vulnerability to security risks and natural disasters
Source water supply, treatment, and finished water transmission facilities must func-
tion as a complete system to provide a safe, reliable source of drinking water to the wa-
ter distribution system. The water treatment improvements design must take all three types
of facilities into consideration to ensure a proper transition between systems.

Upgrading or Expansion of Existing Facilities
Many water treatment plant design projects involve modifying existing facilities to pro-
vide increased capacity, to improve treatment performance, or to modernize and renovate
equipment and structures. These projects require special considerations and investigations
that are not required when one is designing a new plant on a new site.
Investigations made during preliminary design for these types of projects must answer
questions such as the following: