(1) The design engineer shall design LOSS to facilitate operation, monitoring and maintenance. The design of cleanouts and monitoring ports must be consistent with good engineering practice and the department's recommended standards and guidance for pressure distribution systems.

(2) All accesses to LOSS components must be designed to:

(a) Allow for monitoring and maintenance activities;

(b) Prevent unauthorized access; and

(c) Minimize confined space entry. Confined space entry is regulated by department of labor and industries under chapter 296-809 WAC, Confined spaces.

(3) The design engineer shall design and verify that the LOSS meets the following minimum requirements:

(a) Service access ports must be installed at finished grade for all LOSS components;

(b) Monitoring ports must:

(i) Be a minimum of four inches in diameter;

(ii) Extend from the infiltrative surface of the drainfield to final grade;

(iii) Have a cap or cover to stop precipitation from entering them; and

(iv) Be anchored so they remain in place.

(c) Mechanical and electric distributing valves, if used, must be accessible to allow verification that they are working properly;

(d) Controls and warning devices must be clearly accessible and visible including, but not limited to:

(i) Process controls, such as measuring devices, float and pressure activated pump on-off switches, pump-run timers, and process flow controls;

(ii) Diagnostic tools, such as dose cycle counters and flow meters on either the water supply or sewage stream or hour meters on the sewage stream; and

(iii) Alarms.

(e) Audible and visual alarms must be placed on a circuit independent of the pump circuit.