Developing a Project Technical Criteria Document - Design-Build for Water and Wastewater Projects - page 167

in the future. Identifying this possibility allows for the hydraulics design to incorporate
enough flow to allow this extra capacity to be realized.
Plant effluent flow (e.g., 20 mgd or 75.7 ML/d) requirements and unit process perfor-
mance guarantees are also stated at this time. It should be noted that unit process perfor-
mance guarantees are not recommended unless there is a regulatory limit associated with
them. For example, surface water plants in California are expected to achieve less than
2 ntu from clarifiers upstream of filters to minimize microbiological risk in the facility. In
this case, it is reasonable to make the 2-ntu limit a process guarantee; however, stating a
requirement of 1 ntu for clarified water adds risk and uncertainty for the design-builder
and is not a regulatory requirement.
Design criteria and requirements for the secondary facilities. The owner can also
describe performance-based or prescriptive criteria for the secondary systems, such as
chemical and/or polymer systems, service water, compressed air systems, and sampling
systems. Owners may also choose to define performance guarantees for chemical
consumption. For example, prescriptive criteria would be the details for the components
and design of a coagulant feed system, including the chemical dose ranges to be applied.
A performance-based criterion would be to achieve enhanced coagulation, as defined by
the prevailing regulatory agency.
Site design and environmental criteria. In this section of the technical criteria
document, the considerations and requirements for use of the project site and potential
off-site impacts are presented. This includes any information or restrictions for site access
and nearby roads, use of site space for the current project and saving space for the future,
any buried utilities or underground piping, the property boundary, noise, and landscaping.
The owner should also consider informing the bidders if any of these are not priori-
ties. For example, if the owner desires minimal landscaping, guidance on that expectation
should be included.
Design criteria for buildings, structures, and enclosures. Any considerations and
requirements for the layout and design of buildings and structures would be presented in
this section. This includes any space requirements for interior or exterior places, amenities,
architectural features, aesthetics, and types of materials.
For example, if the paint color for equipment, such as filter vessels, is selected to
blend into surroundings and be less noticeable to neighbors to the facility, it should be
highlighted in the technical criteria.
Mechanical design criteria. The primary purpose of this section is to identify the
considerations and requirements for mechanical systems, such as process pumping and
piping, plumbing and drainage, and heating, ventilating, and air conditioning (HVAC).
Electrical design criteria. Owners will want to carefully document utility
coordination requirements for electrical systems for any new infrastructure. This also
includes information on the distribution architecture, indoor/outdoor location options,
and requirements for power quality.
The owner may also choose to use performance guarantees to assess power quality
and consumption during operation.
Instrumentation and control design criteria. Owners typically have a preference for
instrumentation and control (I&C) features. Any requirements for the system architecture
and hardware should be identified. Also, any requirements for the integration of new