(1) Only installers may construct OSS, except as noted under subsection (2) of this section.
(2) The local health officer may allow the resident owner of a single-family residence not adjacent to a marine shoreline to install the OSS for that single-family residence.
(3) The installer described by either subsection (1) or (2) of this section shall:
(a) Follow the approved design;
(b) Have the approved design in possession during installation;
(c) Make no changes to the approved design without the prior authorization of the designer and the local health officer;
(d) Only install septic tanks, pump chambers, and holding tanks approved by the department;
(e) Be on the site at all times during the excavation and construction of the OSS;
(f) Install the OSS to be watertight, except for the soil dispersal component;
(g) Cover the installation only after the local health officer has given approval to cover; and
(h) Back fill with six to twenty-four inches of cover material and grade the site to prevent surface water from accumulating over any component of the OSS.
[Statutory Authority: RCW
43.20.050. WSR 05-15-119, § 246-272A-0250, filed 7/18/05, effective 7/1/07.]