Onsite Inspections

Standard Drainfield Inspections

Inspections Required:

Call for a pre-cover inspection when the drainfield in installed and the filter fabric is in place, but before the system is backfilled. You will also need to water test the tank and riser for the pre-cover inspection. Block the inlet and outlet of the septic tank and fill the tank 2 inches up into the riser and hold for the inspector to verify. The septic tank may be partially backfilled, but leave the top one foot of the tank exposed on all four sides. When you are ready for the pre-cover inspection, submit (send or fax) the ‘as-built’ * drawing and materials list (Final inspection request and notice form). Inspection requests are usually processed in three to seven working days.

PLEASE help us help you by including a vicinity map so we can locate your property easily and by posting the orange address cards at the access point to the property conspicuously.

Capping Fill Drainfield Inspections

Inspections Required:

Scarification inspection: The drainfield area must be inspected for scarification, soil texture, and moisture content prior to cap placement. Arrange with the inspecting sanitarian to leave samples of the cap for approval, either on the site, or at the office.

Pre-cover inspection: Call for inspection when the drainfield gravel, pipe and filter fabric are in place, but before the system is covered or capped.

Cap placement inspection: Call for inspection after the cap is placed, to determine that there is good contact between the native soil and the cap (no obvious contact zone visible), cap depth is adequate (16 inches over filter fabric), and uniform distribution of fill material.

Final inspection: Call for inspection after the landscaping has been started and the area is protected from any livestock or traffic. A Certificate of Satisfactory Completion may be issued upon successful completion of these four inspections.

Pressure Distribution Drainfield Inspections

Inspections Required:

Pre-cover and squirt test inspection. Drainfield trenches have been dug, 6 inches of gravel under the pipe has been placed and leveled. The manifold pipe (bedded in soil) and the drainfield pipe, with risers, are in place. Septic tank is placed and filled with fresh water. Pump package and risers are in place. During the inspection the sanitarian will verify the drainfield has been installed to all the permit requirements, and that the residual head (squirt) is a minimum of 5 feet with no more than 10% variation.

After this inspection, 4 inches of gravel shall be placed over the pipe, the filter fabric placed over the entire surface of the gravel, and the system backfilled with a minimum of 12 inches of soil.

The second inspection, if possible, can be combined with the first inspection if:

Septic tank is filled with water and there is water to the site which can be used to top off the tank to check the float switches 'on' level, AND
The pump and alarm circuit have been hard-wired through the control/alarm panel. Sanitarian will check alarm function (audio and visual) and will check the dose volume setting of the float switch. Results should match the submitted hydraulic design criteria.

Bottomless Sand Filter Drainfield Inspections

Inspections Required:

Inspection 1:

Container location and dimensions conforms to approved plot plan, has been installed level, and has not been countersunk deeper than permitted.
Ground surface within the container side walls has been scarified. The resulting exposed soil surface is level, and it is not compacted. Do not remove any soil (except what is permitted for countersinking the container) when scarifying the ground surface; only remove the vegetative matter.
Container constructed of ¾ inch plywood (or oriented strand board--edges sealed.)

Inspection 2:

Approvable sieve analysis received for underdrain media.
Approvable sieve analysis received for the Sand Media, and all Sand Media for this job has been delivered to the site.
Minimum 6” approvable underdrain media (E.G. “DEQ Pea Gravel”)evenly installed.
(DO NOT INSTALL DRAIN ROCK NOR FILTER FABRIC AT THIS POINT).
Sand Media sampled at job site. It will be tested for spec. conformance.
Sand Media sample tested and approved. Installer notified to proceed with Sand Media installation.
Note: The underdrain media and Sand Media must be installed “clean” (free from soil and debris), and it must be protected from contamination from soil and debris after it has been installed. Do not install the Sand Media until notified of approved test results by Environmental Health.

Inspection 3:

Minimum 24" approved Sand Media installed. Sand to be damp when installed.

Inspection 4:

IMPORTANT: THE SEWAGE PUMP IS TO BE HARDWIRED TO A CONTROL BOX WITH AN APPROVED SEWAGE PUMP ELECTRICAL INSPECTION PRIOR TO INSPECTION #4 BEING PERFORMED. TEMPORARY POWER SERVICE, OR USE OF A GENERATOR, CONNECTED TO THE CONTROL BOX IS ACCEPTABLE FOR PERFORMING PUMP TESTS. DO NOT INSTALL CHECK VALVES WITHOUT SANITARIAN APPROVAL. (Sewage pump electrical inspection approved)
Tank(s) are sized as per permit, located as per approved plot plans, with at least 1 approved riser extending to the projected finished grade, and pass the in-the-field watertightness test.
APPROVABLE 2-COMPARTMENT TANK EQUIVALENCY REQUIRED FOR ALL SEPTIC PERMITS ISSUED AFTER 010103 WHERE PUMPS REQUIRED. THESE TYPES OF PERMITS ISSUED PRIOR TO 010103 WILL NEED TO MEET THE 2-COMPARTMENT EQUIVALENCY BEGINNING 060103.
The pump, screen vault, riser, and float set-up is approvable. The pump and filter are to be removable through use of only quick disconnects without unscrewing piping. Installation of elbows is not necessary unless otherwise required.
Minimum 3" approved underdrain media (or drain media) under the pressure distribution laterals, and laterals installed level.
The transport, manifold, and pressure distribution piping is located and conforms to an approved design.
Distribution orifices (drilled with 1/8 in burless bit) oriented downward, except one orifice at each end of each lateral is oriented upward. Each orifice equipped with a removable slotted-faced shield.
Distal end of each lateral consists of an approved long radius elbow, or 2-45 degree elbows, riser with clean-out. Riser to extend to projected finished grade and is covered with a valve box type container and lid for easy access and location purposes. Box filled with DEQ pea gravel.
Minimum 5' squirt height from all upward facing orifices with no more than a 10% height variation throughout the system. Laterals must be flushed out prior to this pump pressure test.
Approvable anti-siphon valve installation (if valve necessary)
Transport piping freeze protected.
Pump dosing test: Maximum dosing is 10% of permitted daily flow rate.
Pump flow rate (for one compartment tanks only): Maximum flow rate is 35 gpm Flow rate =dosed volume/dose time
Pump alarm audio and visual test.
Approvable sandfilter monitoring port installation.

Inspection 5:

Approved underdrain media (or drain media) installed evenly to cover tops of all laterals and shields.
Approved filter fabric completely covers the top layer of underdrain or drain media.

Inspection 6: (Submit As-Built form for requesting inspection 6)

(Approvable Final Septic Inspection Request and Notice ("As-Built") form received.)
Sand filter container backfill approvable--10" unsettled (6" settled) over top of side walls and to 14" unsettled(10" settled) over the center of the container. Backfill from the top of the container sides to the ground surface must be at a 3-to-1 slope.Backfill over top of container is not compacted—backfill around container is firm.

Reminders:

A shallow rooted vegetative cover (e.g. grasses, wildflowers (no trees)) to be established and maintained over the top of the sand filter container and the drainfield.
Maintain the septic tank(s) and absorption facility components per manufacturer’s specifications.

Please do not rely on your neighbors for advice. Rules and procedures changed in April of 1995. Feel free to call the sanitarian that issued the permit if you have any questions. When you call, please have the sanitarian's initials and the permit number (ex. S12345) available (both are on your copy of the drainfield construction permit.) If you do not reach the sanitarian on the first try, it is possible the sanitarian is in the field performing inspections so please leave your permit number, question and phone number on the voice mail. That way the sanitarian may be able to pull your paperwork, research your question and return your call upon returning from the field.