(1) Collection and conveyance systems and their sewer pipes, manholes, air release valves, lift stations, and other appurtenances must be designed and constructed to prevent contamination of drinking water, and protect ground and surface water, public health, and the environment from contamination with untreated or partially treated sewage.
(2) The design and construction of LOSS piping must be consistent with good engineering practice, the department of ecology's publication "Criteria for Sewage Works Design," August 2008, and the department of ecology and department of health publication "Pipeline Separation Design and Installation Reference Guide," July 2006.
(3) LOSS piping systems must be designed to prevent infiltration and inflow of groundwater, surface water and stormwater.
(4) The department may require owners of existing LOSS to conduct infiltration and inflow analysis and may require repair and replacement of piping and appurtenances to reduce infiltration and inflow.
[Statutory Authority: RCW
70.118B.020. WSR 11-12-035, § 246-272B-06500, filed 5/25/11, effective 7/1/11.]