Department of
Environmental Quality

Wastewater reuse consists of spent or used water from a home, community, farm, or industry that contains dissolved or suspended matter. Land application is one method of reusing wastewater. It is a natural way of reusing wastewater by which it is is applied to land for irrigation and is absorbed by the crop or assimilated into the soil structure. Other methods of reuse include commercial toilet flushing, dust control, and fire suppression.

Wastewater reuse may contain any of a number of types of chemicals and, in some cases, human pathogens. To protect public health and prevent pollution of surface and ground waters, Idaho's Recycled Water Rules (IDAPA 58.01.17) require anyone wishing to land-apply or otherwise use wastewater reuse to obtain a permit before constructing, modifying, or operating a reuse facility in the state. (The rules do not apply to feedlots, dairies, and mining.)

DEQ is the state agency assigned responsibility by the Idaho Legislature to issue wastewater reuse permits in the state. Two types of wastewater reuse permits are issued—industrial and municipal. Industrial permits regulate wastewater reuse from such operations as food processing facilities. Municipal permits regulate wastewater reuse that contains treated sewage. All wastewater reuse permits specify both standard and site-specific conditions. Additional requirements apply to municipal permits.

Standard Permit Conditions

All wastewater reuse permits require permittees to properly maintain and operate their treatment, control, and monitoring equipment; respond to DEQ's requests for relevant information; provide access to the permitted facility to inspect equipment, operations, and records and to monitor compliance; and report information pertaining to planned physical or operational changes and noncompliance episodes. Failure to comply may result in civil penalties and revocation of the permit. Wastewater reuse permits are issued for terms of five years, after which the permittee is responsible for applying for a new permit to continue operation.

Odor Management

Because odors may be of concern to neighbors of wastewater treatment plants, reuse facilities, and other operations associated with these facilities, all wastewater reuse permits prohibit these facilities from creating a public health hazard or nuisance conditions including odors. Permittees are required to develop nuisance odor management plans outlining specific design considerations, operation and maintenance procedures, and management practices that will be employed to minimize the potential for or limit odors. Plans also must include procedures for responding to odor incidents and notifying the public if an incident occurs.

Specific Permit Conditions

Because of varying environmental conditions and wastewater compositions, wastewater reuse permits also prescribe specific permit conditions based on the characteristics of the recycled water to be reused, the geology and climate at the facility site, the size of the facility and its proximity to populated areas and to ground and surface water, techniques that may be used to distribute the wastewater reuse, abilities of the soils and vegetative covers to treat the wastewater reuse, or other conditions relevant to the type of reuse involved.

Specific permit conditions differ from facility to facility and may specify or limit wastewater composition; the method, manner, and frequency of wastewater reuse; pretreatment requirements; and the physical, chemical, and biological characteristics of the wastewater reuse. Varying compliance schedules as well as monitoring and reporting requirements may be imposed as well.

Municipal Wastewater Reuse Requirements

Municipal wastewater reuse is often used to irrigate farmlands, orchards and vineyards, golf courses, cemeteries, parks, playgrounds, schoolyards, and other areas. Because of the nature of this wastewater reuse and its potential exposure to humans and animals, certain specific treatment requirements apply to municipal wastewater reuse. For example, monitoring requirements include mandatory bacterial sampling. Other specific measurable criteria also must be met, depending on whether the recycled water may come into contact with edible or inedible portions of raw food crops, fruit, fodder, seed, and processed food crops. Irrigation may be allowed only during periods of non-use, and public access may be restricted.

Application and Processing Procedures

The wastewater reuse permit application process begins with the applicant submitting a pre-application form and scheduling a pre-application meeting with DEQ at which application requirements are discussed. Applicants are then required to submit to DEQ an application including site-specific information, facility and topographic maps, and wastewater reuse-specific information.

• Wastewater Reuse Permit Pre-Application Form

Upon receipt of the application, DEQ reviews the applicant's information and, if all requirements have been met, issues a completeness determination within 30 days. If the application is determined to be complete, DEQ will then set the effective date of the application. Within 30 days following the effective date of the application, DEQ will issue a preliminary decision to prepare a draft permit or deny the application. Following a decision to prepare a draft permit, DEQ will prepare the draft permit within 60 days. The public is then notified that a draft permit has been issued and is given an opportunity to comment. The effective date of the final permit is generally 60 days after the draft permit has been issued.