Recycling Treated Municipal Wastewater for Industrial Water Use

Appendix B
Status of Water Reuse Regulations and Guidelines
The standards in states having the most reuse experience tend to be more stringent than
those in states with fewer reuse projects. States that have water reuse regulations or
guidelines typically set standards for reclaimed water quality and specify minimum
treatment requirements, although a few states, such as Texas and New Mexico, do not
prescribe treatment processes and rely solely on water quality limits.
Regulatory Requirements for Nonpotable Uses of
Reclaimed Water
In the past, most state water reuse regulations were developed in response to a need to
regulate a growing number of water reuse projects in the particular state. Recently, some
states that currently have few reuse projects have taken a proactive approach and have
adopted criteria, which tend to encourage implementation of projects. Arizona,
California, Florida, and Texas, which have had comprehensive criteria for a number of
years, have revised their water reuse regulations within the last ten years to reflect
additional reclaimed water uses, advances in wastewater treatment technology, and
increased knowledge in the areas of microbiology and public health protection.
Common Uses
The variations and inconsistencies among state regulations are illustrated in Table 4,
which includes examples of several states’ reclaimed water standards for uses ranging
from fodder crop irrigation to toilet and urinal flushing in buildings.
Water reuse regulations focus on public health implications of using the water, and water
quality criteria not related to health protection usually are not included in water reuse
regulations. Most states with extensive water reuse experience have comparable,
conservatively-based water quality criteria or guidelines. Arguments for less restrictive
standards are most often predicated upon a lack of documented health hazards rather
than upon any certainty that hazards are small or nonexistent. In the absence of
definitive epidemiological data and a unified interpretation of scientific and technical
data on pathogen exposures, selection of water quality limits will continue to be
somewhat subjective and inconsistent among the states. Regulatory requirements for
some nonpotable uses of reclaimed water not included in Table 4 are discussed below.
Wetlands
In most cases, the primary intent in applying reclaimed water to wetlands is to provide
additional treatment of effluent prior to discharge or reuse, although wetlands are
sometimes created solely for environmental enhancement. In such cases, secondary
treatment is usually acceptable as influent to the wetland system. Very few states have
regulations that specifically address the use of reclaimed water for creation of artificial
wetlands or the restoration or enhancement of natural wetlands. Where there are no
regulations, regulatory agencies prescribe requirements on a case-by-case basis. In
addition to state requirements, natural wetlands, which are considered waters of the
United States, are protected under EPA's NPDES Permit and Water Quality Standards
programs. Constructed wetlands built and operated for the purpose of wastewater
treatment generally are not considered waters of the United States.
Craddock Consulting Engineers B-5
In Association with CDM & James Crook
WWReuse Tm1_Appendix B_Regulatory.doc