Section 444.8372 - System utilizing graywater for underground irrigation: Application to construct, alter or install system; design criteria1. An application to construct, alter or install a system that uses graywater for underground irrigation must include:(a) Detailed plans of the system to be constructed, altered or installed;(b) Detailed plans of the existing and proposed sewage disposal system; and(c) Data from percolation tests conducted in accordance with NAC 444.796 to 444.7968, inclusive.2. A holding tank for graywater must: (a) Be watertight and constructed of solid, durable materials that are not subject to excessive corrosion or decay.(b) Have a minimum capacity of 50 gallons.(c) Have an overflow and an emergency drain. The overflow and emergency drain must not be equipped with a shutoff valve.3. A three-way diversion valve, emergency drain and overflow must be permanently connected to the building drain or building sewer and must be located upstream from any septic tanks. The required size of an individual sewage disposal system must not be reduced solely because a system that uses graywater for underground irrigation is being used in conjunction with the individual sewage disposal system.4. The piping for a system that uses graywater for underground irrigation which discharges into the holding tank or is directly connected to the building sewer must be downstream of any vented trap to protect the building from possible sewer gases.5. The estimated discharge of a system that uses graywater for underground irrigation must be calculated based on the number of bedrooms in the building, as follows: (a) For the first bedroom, the estimated discharge of graywater is 80 gallons per day; and(b) For each additional bedroom, the estimated discharge of graywater is 40 gallons per day.6. The absorption area for an irrigation system that includes a system that uses graywater for underground irrigation must be calculated in accordance with the following table: | Percolation Rate (minutes per inch) | Minimum Square Feet Per 100 Gallons Discharged Per Day |
| 0-20 | 20 |
| 21-40 | 40 |
| 41-60 | 60 |
Nev. Admin. Code § 444.8372
Added to NAC by Bd. of Health by R129-98, eff. 3-25-99