Section 444.804 - Construction of septic tank1. Plans for a septic tank which have not been previously approved by the health authority must be submitted to the health authority for approval. The plans must show all dimensions, reinforcing, structural calculations and such other pertinent data as may be required pursuant to NAC 444.804 to 444.810, inclusive. A septic tank must be constructed of solid durable materials, and must not be subject to excessive corrosion or decay. Acceptable materials include concrete, coated steel, polyethylene, fiberglass and any other material approved by the health authority.2. A septic tank must have two compartments. The capacity of the inlet compartment must be not less than 2/3 of the total capacity of the tank. The inlet compartment must be at least 3 feet in width and 5 feet in length. The depth of the liquid in the inlet compartment must be not less than 30 inches or more than 72 inches. The secondary compartment must have a minimum capacity of 300 gallons and a maximum capacity equal to 1/3 of the total capacity of the septic tank. If the septic tank has a total capacity of more than 1,500 gallons, the secondary compartment must be 5 feet or more in length.3. Adequate access must be provided into each compartment to facilitate inspection and cleaning of the tank. Each compartment must have at least one manhole to provide access into the compartment. A manhole must have a minimum diameter of 20 inches. If the inlet compartment is longer than 12 feet, an additional manhole must be provided over the baffle or partition wall.4. An inlet pipe and an outlet pipe must each be at least 4 inches in diameter. The top of the tee or baffle for both the vented inlet and the vented outlet must extend at least 4 inches above the level of the liquid. The bottom of the tee or baffle for both the vented inlet and vented outlet must extend at least 12 inches below the level of the liquid. The invert of the inlet pipe must be at least 2 inches above the invert of the outlet pipe.5. A manufactured septic tank must be permanently and legibly marked as to the manufacturer, total tank capacity, liquid capacity and general location of the manufacturing firm.6. A partition or baffle between compartments must be made of solid, durable material, must extend at least 4 inches about the liquid level, and must be vented to allow for the free passage of gas between the compartments. A down-turned 90-degree inverted fitting, which is at least 4 inches in diameter, must be installed on the side of the baffle or partition for the inlet compartment. The inverted fitting must be set so that the bottom of the fitting is placed at a level that is equal to not less than 50 percent or more than 75 percent of the height of the liquid level in the tank. A baffle or partition may not be made of wood.7. A septic tank must be structurally designed to withstand all anticipated loads of dirt or other substances, must be installed so that the tank is level and must be installed on a solid bed. The cover of a septic tank must be capable of supporting a load of dirt of not less than 300 pounds per square foot.8. All aggregates fine and coarse, other than lightweight aggregate, must conform to specifications outlined by the Standard Specifications for Public Works Construction adopted by reference pursuant to NAC 444.7825.9. Aggregates must be free of deleterious substances which may react with oxidized hydrogen sulfide. Aggregates must be graded in such a manner as to produce a homogeneous concrete mix. All materials must be accurately weighed at a central batching facility for mixing.10. All cement must be Portland cement conforming to the Standard Specifications for Public Works Construction adopted by reference pursuant to NAC 444.7825. Cement content must be sufficient to produce a minimum strength of 3,000 PSI, or other design strengths required.11. All concrete must be handled from the mixer or transport vehicle to the place of final deposit in a continuous manner, as rapidly as practicable, and without segregation or loss of ingredients, until the approved construction is completed. Each pour must be compacted by mechanical internal or external-vibrating equipment. Duration of the vibration cycle must be limited to the time necessary to produce satisfactory consolidation without causing objectionable segregation.12. All reinforcing steel, including welded wire mesh, must be of the size and in the location as shown on the plans. The reinforcing steel must be sufficiently tied to withstand any displacement during the pouring operation. All bars must be made of intermediate or hard graded billet steel. The health authority may inspect the tank reinforcing steel before any concrete is poured.13. The side walls of a septic tank must extend at least 9 inches above the level of the liquid. The interior ceiling of the septic tank must be at least 2 inches above the top of the tee or baffle for the vented inlet and the top of the tee or baffle for the vented outlet.14. A septic tank must be watertight. A manufacturer of a septic tank shall test the tank for watertightness by one of the following methods: (a) Water testing by sealing the outlets, filling the septic tank to its operational level and allowing the tank to stand not less than 8 hours or more than 10 hours. If, after this period, there is a measurable loss of water, the tank must be refilled and allowed to stand for an additional 8 to 10 hours. If, after the second period, there is a measurable loss, the tank must be rejected. A septic tank may not be rejected solely because of the appearance of damp spots on the exterior of the tank. A tank that has been rejected must be repaired and tested before it may be used in an individual sewage disposal system.(b) Vacuum testing by sealing all of the inlets, outlets and accesses and introducing a vacuum of 4 inches of mercury. If the vacuum drops during the first 5 minutes, the vacuum must be brought back up to 4 inches of mercury. If the septic tank fails to hold the vacuum at 4 inches of mercury during the second 5-minute period, the tank must be rejected. A tank that has been rejected must be repaired and tested before it may be used in an individual sewage disposal system.(c) An alternative testing procedure approved by the health authority.15. The health authority may require a manufacturer of a septic tank to demonstrate the watertight integrity of the septic tank.16. A septic tank must meet the requirements set forth in the Uniform Plumbing Code for the construction of septic tanks.Nev. Admin. Code § 444.804
Bd. of Health, Indiv. Sewage Disposal Systems Reg. § 1 of Note, eff. 1962; A and renumbered as § 12.6.2, 11-23-72 & renumbered as §§ 12.6.1, 12.6.3-12.6.11, part 12.7, & part 12.8, eff. 11-23-72-NAC A by R129-98, 3-25-99