Recycling Treated Municipal Wastewater for Industrial Water Use

Section 2
Implementation Considerations
Craddock Consulting Engineers 2-11
In Association with CDM & James Crook
TM1-Sec2_0707.doc
While many industrial uses require water of higher chemical quality than that
typically present in reclaimed water (e.g., computer chip manufacturing requires
reverse osmosis treatment to produce ultra-pure wash water), water reuse regulations
are intended to provide health protection and only include requirements to attain that
end.
Miscellaneous Nonpotable Uses. While all states that have water reuse regulations
or guidelines include criteria for crop and/or landscape irrigation, some include
requirements for less common uses of reclaimed water, such as flushing sanitary
sewers, street cleaning, dust control, soil compaction, making concrete, snowmaking,
decorative fountains, commercial laundries, commercial car washes, equipment
washing, and fire protection systems. For these and similar uses, the various state
standards impose wastewater treatment process requirements, reclaimed water
quality limits, and design and operational requirements reflective of the degree of
human exposure to the water that are in concert with other more common uses of
reclaimed water.
For example, secondary treatment with a minimal level of disinfection is acceptable
for uses where there is little or no expected human contact with the water, such as
flushing sanitary sewers or making concrete. Conversely, uses such as snowmaking
and vehicle washing are likely to result in contact with the reclaimed water, and
tertiary treatment with a high level of disinfection is usually required.
Regulatory Mandates
States such as California and Florida have regulations that mandate water reuse
under certain conditions. The Florida Water Policy [Florida Department of
Environmental Protection, 1995] establishes a mandatory reuse program that is
actively enforced. The policy requires that the state’s water management districts
identify water resource caution areas that have water supply problems that have
become critical or are anticipated to become critical within the next 20 years. State
legislation requires preparation of water reuse feasibility studies for treatment
facilities located within the water resource caution areas, and a “reasonable” amount
of reclaimed water use from municipal wastewater treatment facilities is required
within the designated water resource caution areas unless reuse is not economically,
environmentally, or technically feasible. Water reuse also may be required outside of
designated water resource caution areas if reclaimed water is readily available, reuse
is economically, environmentally, and technologically feasible, and rules governing
the imposition of requirements for reuse have been adopted in those areas by the
water management district having jurisdiction.
In California, laws and regulations exist that mandate water reuse under certain
conditions. Section 13550 of the California Water Code states that the use of potable
domestic water for nonpotable uses, including, but not limited to, cemeteries, golf
courses, highway landscaped areas, and industrial and irrigation uses, is a waste or
an unreasonable use of the water if reclaimed water is available which meets certain
conditions [California State Water Resources Control Board, 2000]. The conditions