Developing a Project Technical Criteria Document - Design-Build for Water and Wastewater Projects - page 164

Table 13-1. Example prescriptive and performance criteria for a pumping application

Parameter Design Criteria

Prescriptive Design Criteria
Design Capacity

10,000 gpm at 100 ft

Pump Type Vertical turbine (refer to specification 10350)

Number of Pumps 3 at 3,350 gpm operating + 1 at 3,350 gpm standby

Wet Well Reinforced concrete with 0.5 mil gal minimum working

volume

Drive Type Adjustable frequency (refer to specification 16060)

Motors (Refer to specification 16050)

Performance Design Criteria
Design Capacity 3,000 gpm to 10,000 gpm at 100 ft

Pump Type Horizontal split case, vertical turbine/concrete wet well or

can-type vertical turbine

Number of Pumps 2 minimum + 1 standby equal to largest unit

Drive Type Constant speed or adjustable frequency such that number of

restarts per any pumping unit does not exceed 3 per hour

Primary performance guarantees. Primary process performance guarantees for
WTPs and WWTPs mirror the prevailing regulatory standards (Canney 2006). For WTP
projects, guarantees would reflect Safe Drinking Water Act (SDWA) standards and any
other limits that have been established by the state agencies. For WWTP projects, primary
guarantees reflect the National Pollution Discharge Elimination System (NPDES)
standards and other limits that have been established by state agencies or local boards.
Secondary performance guarantees. Some owners establish secondary performance
guarantees that require performance beyond the limits or criteria set by regulatory
agencies (Canney 2006). Secondary performance guarantees may also be operational set-
points or targets. Examples of secondary guarantees are as follows:
• Unit process guarantees
• Operational reliability guarantees
• Community/environmental guarantees
• Consumptive guarantees
An example of unit process guarantee is the turbidity from a WTP sedimentation
basin. An operational guarantee might be a time limit for when standby units are brought
online when the duty system fails. Community and environmental guarantees might be
for noise or odor, and consumptive guarantees are for chemical use or power use.
Secondary performance guarantees are project specific. Both the owner and the pro-
poser must be cautious in establishing and agreeing to these types of performance guar-
antees because standard protocols often do not exist. As a result, the guarantee language
must be very specific to avoid misunderstandings.