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3.4 CHAPTER THREE

• Plant flow schematics indicating all treatment units and equipment for both the primary
treatment processes and waste handling systems
• Conceptual plant layouts showing the arrangement of treatment process units and other
related facilities with respect to site topography
• Plant hydraulic profile establishing operating water elevations through the plant at nor-
mal and peak flow rates, for both the primary treatment process and waste handling
system
• Design criteria establishing treatment unit sizes and specific design factors for mini-
mum, average, and maximum flow conditions of the major treatment processes and
waste handling systems
• Requirements for ancillary facilities including space needs for plant administration, lab-
oratory, maintenance, chemical handling and storage, low and high service pumping,
and water storage
• Plant control concepts including plant control logic, control system architecture, and
communications with off-site facilities
• Treatment waste handling and ultimate disposal scheme, including off-site waste trans-
port requirements
• Architectural and structural concepts for the plant buildings and structures, including
weather protection provisions for the treatment facilities
• Provisions for future expansions of the plant facilities, allowing for addition of equip-
ment and treatment process units, with plant infrastructure oversized where appropri-
ate
• Security measures required to provide the necessary protection of the plant facilities
and ensure plant reliability

Financial Feasibility Evaluation
Financing for a water treatment plant project should be finalized during, or immediately
after, the preliminary design phase, when sufficient information is available to establish
a valid project budget. Preliminary estimated costs for plant facilities should be devel-
oped, including the implementation schedule, approximate cash flow, and operations and
maintenance costs, that establish projected annual costs for the new facility. Potential
sources of revenue for financing the project must then be investigated to establish a vi-
able program to fund the planned facility. AWWA Manual M29, Water Utility Capital
Financing, provides a comprehensive overview of traditional and innovative financing
sources that should be evaluated by water utility management in determining short- and
long-term strategies for meeting capital requirements.

Ongoing Coordination and Cost Evaluations
During the preliminary design phase, design development should be coordinated with all
support disciplines to obtain input on the overall design. This coordination is necessary
to make sure that preliminary engineering does not overlook any design issues that could
affect critical design decisions. Although the process and civil disciplines are normally
the primary focus of the preliminary engineering phase, the architectural, structural, me-
chanical, electrical, and instrumentation support disciplines should be included in these
discussions.