Nevada County Municipal Code Ch. 3 Graywater Systems

For the purpose of this Chapter, certain words and phrases are defined and certain provisions shall be construed as herein set forth unless it shall be apparent from their context that they have a different meaning:

A. Blackwater means liquid and solid human body waste and the carriage waters generated through toilet usage.

B. Dwelling means any housing unit constructed for the purpose of housing one (1) or more families and includes mobile homes, trailers, etc.

C. Graywater means that wastewater from a dwelling which does not contain human or animal excreta, offal, or food matter and includes waste from sinks, washing machines, and other plumbing fixtures but not toilets, bidets, and kitchen sinks.

D. Environmental Health Department means the Environmental Health Department of the County of Nevada.

E. Environmental Health Director means the Environmental Health Director of the County of Nevada, or their duly authorized representative.

F. Person means any person, firm, association, organization, partnership, business, corporation or company.

G. Septic Tank means a watertight receptacle which receives the discharge of a drainage system or part thereof designed and constructed so as to retain solids, digest organic matter during a period of detention, and allow the effluent to drain into an absorption system.

H. Sewage means any and all waste substances, liquid or solid, associated with human habitation, which contain or may be contaminated with human or animal excreta or excrement, offal or any feculent matter and includes all liquid waste from toilets, bidets and kitchen sinks.

I. Sewage Disposal System means any sewer system, sewage disposal plant, septic tank, drainage system, seepage pit, chemical toilet, privy or any other facility constructed for the purpose of receiving sewage or its effluent.

(Ord. 1802. (09/08/1992); Ord. 2531. (10/24/2023))

Graywater may be utilized for purposes of irrigation of plants if the owner of the building has in their possession a current valid graywater discharge permit from the County. Such a permit is revocable for noncompliance with standards of graywater use as outlined in this Section. Graywater usage shall not be permitted if plumbing fixtures have been utilized for the purposes of cleaning sections contaminated with feculent matter, such as diapers, animal bedding, incontinent garments, and related. Additionally, graywater shall not be discharged onto the ground if it is contaminated with hazardous chemicals, such as resulting from changing vehicle oils, photographic developing, degreasing, drain cleaners, and related materials.

(Ord. 1802. (09/08/1992); Ord. 2531. (10/24/2023))

A. Plumbing. Graywater may be collected and disposed of as allowed for under this Section if, at the time of installation of plumbing in the building, a dual waste water plumbing system was installed in such a way that no waste water from kitchen sinks, toilets, or bidets can, under any circumstances, intermingle with the other waste water system (graywater system). No cross connection between the two (2) systems shall be allowed.

Alternatively, a building may be retrofitted with plumbing to allow the reuse of some graywater by directing wastewater from the washing machine, sinks other than kitchen sink, bathtub, shower, or other fixture excluding toilets, bidet and kitchen sink.

In the case of both approaches above, the Nevada County Building Department must attest to the Environmental Health Department at the time for which the graywater discharge permit is applied that the separate graywater plumbing system conforms to these requirements.

B. Graywater Treatment Systems. Treatment of graywater before it is applied as irrigation to plants may be accomplished in a number of ways at the discretion of the owner of the building. These may include, but shall not be limited to the following:

1. Direct application with no treatment.

2. Sand filtration with subsequent application.

3. Disinfection with chlorine or other substance, and subsequent application.

4. Settling and biological treatment in a buried septic tank which is not contaminated by untreated sewage (blackwater), with subsequent application.

5. Filtration with some method other than sand filter.

6. Some other method as proposed by the owner of the building and acceptable to the Environmental Health Department.

C. Application Methods. Graywater may be applied in irrigation of plants by any of the following methods:

1. Distribution through a drip irrigation system under the pressure of gravity alone.

2. Distribution through a drip irrigation system under pressure generated by a pump, pressure tank, or elevated holding tank.

3. Subsurface distribution by way of buried perforated pipes or leaker hose, or trenches and beds specifically designed for that purpose.

4. Episodic application into irrigating wells consisting of pipes installed vertically into the ground and filled with gravel to allow a temporary reservoir within the pipe which oozes out and is absorbed into the soil from the bottom of the pipe. This method is usually utilized for irrigating large trees.

D. The following application methods will not be allowed:

1. Spraying or sprinkling into the air.

2. Flooding of an area in such a manner that standing water accumulates for a period of time to contribute to nuisances such as odors and insect breeding.

3. Discharge to the surface which can run off into seasonal streams, or any other geological formation which could allow the graywater to come to flow directly into surface water.

4. Application by any method within the setback distances applicable to sewage as referenced in the rules and regulations for private sewage systems pursuant to 15.01.

5. Application which would lead to graywater flowing onto the surface of adjacent property.

(Ord. 1802. (09/08/1992); Ord. 2531. (10/24/2023))

Graywater may be collected in a reservoir as it leaves the building through a separate graywater plumbing system and may then be discharged to the irrigation system or be pumped to another reservoir for subsequent discharge to the irrigation system.

Reservoirs in which graywater is collected and stored shall be maintained in such a way that bacterial growth will not reach levels such that nuisances including odors and insect breeding will develop, and shall be designed in such a way that accidental drowning or human contact with the water in the reservoir is prevented.

Stored graywater may be reserved for use in fire protection but must be maintained to prevent nuisance as discussed above and must be labeled "used water - do not drink."

(Ord. 1802. (09/08/1992); Ord. 2531. (10/24/2023))

The following uses of graywater shall be prohibited:

A. Drinking.

B. Bathing.

C. Used as swimming pool or wading pool water.

D. Irrigation of edible crops where the irrigating water will have routinely come into contact with the edible vegetation such as root crops. Crops where the edible portion grows on the surface of the ground and surface application methods were used. Examples of root crops are carrots and potatoes; examples of crops growing on the surface of the ground include lettuce and strawberries.

E. Discharge through a garden hose which might be inadvertently picked up by someone and either drunk or sprayed at another human being.

F. Returning the graywater to the building for utilization in any way including use in the tank of the toilet for flushing, unless specifically approved by the County Building Department.

(Ord. 1802. (09/08/1992); Ord. 2531. (10/24/2023))

The plumbing of the graywater system exterior to the house shall be such that the graywater can be immediately diverted to an approved sewage disposal system by the process of simply turning some valves. In cases of ground saturation during rainy season, revocation of the graywater discharge permit, malfunction of the graywater accumulation or distribution system, or need to work on the graywater application distribution system, the graywater should be able to be diverted into the sewage disposal system. The calculation of leachfield size for the approved sewage disposal system shall be performed in such a way that all water discharged from the building, both blackwater and graywater, shall be able to be accommodated by the leachfield.

(Ord. 1802. (09/08/1992); Ord. 2531. (10/24/2023))

A permit to discharge graywater in the County of Nevada may be revoked by the Environmental Health Department for any of the following reasons:

A. Non-compliance by the permit holder with the standards of this Section.

B. Evidence documented by the Environmental Health Department of the failure of the graywater system.

C. Determination by the Environmental Health Department that graywater systems of the type permitted have begun to show evidence of failure or have been shown to pose public health risk where permitted and/or installed elsewhere.

D. Determination by the Environmental Health Director that continued functioning of the graywater system poses an imminent health hazard.

(Ord. 2531. (10/24/2023))

Fees for a graywater discharge permit may be set by the Board of Supervisors from time to time by ordinance.

(Ord. 1802. (09/08/1992); Ord. 2531. (10/24/2023))