Wash. Admin. Code § 246-272A-0280 – Repair of failures

(1) When an OSS failure occurs the local health officer shall:
1. (a) Allow an OSS to be repaired using the least costly alternative that meets standards and is likely to provide comparable or better long-term sewage treatment and effluent dispersal outcomes;
2. (b) Permit an OSS meeting the requirements in Table X of this section only if the OSS has failed and the following are not feasible:
  1. (i) Installation of a conforming OSS or component; or
  2. (ii) Connection to either an approved LOSS or a public sewer.
3. (c) Identify repair permits meeting the requirements in Table X of this section for the purpose of tracking future performance;
4. (d) Give first priority to allowing repair and second priority to allowing replacement of an existing conventional OSS, consisting of a septic tank and drainfield, with a similar conventional OSS;
5. (e) Evaluate all unpermitted sewage discharges to determine if they pose a public health threat. If determined by the local health officer to be a public health threat, the local health officer shall require a compliance schedule;
6. (f) Report failures within 200 feet of shellfish growing areas to the department; and
7. (g) Not impose or allow the imposition of more stringent performance requirements of equivalent OSS on private entities than public entities.
(2) The local health officer may:
1. (a) Require a compliance schedule for failures discovered during property transfer inspections;
2. (b) Allow a repair of a failure using ASTM C-33 sand or coarser as fill to prevent direct discharge of treated effluent to groundwater, surface water, or upon the surface of the ground if the vertical separation is less than 12 inches.

(3) The OSS owner shall notify the local health officer when there is a failure and indicate which methods will be used to address the failure in accordance with Table IX of this section:

(a) The owner may use option D only if the local health officer determines options A through C are not feasible and may use option E or F only if options A through D are not feasible.
(b) For options A through F, the owner shall develop and submit information and obtain a permit as required under WAC 246-272A-0200 prior to any repair or replacement of an OSS on the property served or a nearby property if the owner obtains an appropriate documentation including, but not limited to, an easement, covenant, contract, or other legal document authorizing access for construction, operation, maintenance, and repair.

(c) If options A through F are not feasible, the owner shall discontinue use of the OSS, abandon the OSS according to the requirements in WAC 246-272A-0300, and cease all sewage generating activities on the property.

Table IX

Options and Methods to Address an OSS Failure

Options	Method
A	Repair or replace the OSS, with a similar OSS, if the OSS provides comparable or better long-term sewage treatment and effluent dispersal outcomes where:
		1. The effluent treatment and soil dispersal component to be repaired or replaced is not closer to any surface water, well, or spring than the minimum separation distance required in Table IV of WAC 246-272A-0210(1);
		2. The soil dispersal component to be repaired or replaced complies with the treatment level and distribution method requirements in Table VI of WAC 246-272A-0230;
		3. The local health officer has a permit or record of the OSS on file; and
		4. The repair or replacement will not result in an OSS that meets the definition of failure.
B	Repair or replace the OSS with an OSS in compliance with new construction requirements under this chapter.
C	Connect the residence or facility to a:
		1. Publicly owned LOSS;
		2. Privately owned LOSS where it is deemed economically feasible; or
		3. Public sewer.
D	Repair or replace the OSS in conformance with Table X of this section.
E	Use a holding tank.
F	Obtain a National Pollution Discharge Elimination System or state discharge permit from the Washington state department of ecology issued to a public entity or jointly to a public entity and the OSS owner only when the local health officer determines:
		1. An OSS is not feasible; and
		2. The only realistic method of final dispersal of treated effluent is discharge to the surface of the land or into surface water.

(4) When there is an OSS failure, the OSS designer shall:

(a) Evaluate the causes of failure prior to designing the repair or replacement of the OSS;
(b) Prevent the direct discharge of sewage or treated effluent to groundwater, surface water, or upon the surface of the ground;
(c) Meet the horizontal separations under WAC 246-272A-0210(1) to public drinking water sources;
(d) Protect all drinking water sources, shellfish harvesting areas, and water recreation facilities designated for swimming in natural waters;
(e) Minimize nitrogen discharge in areas where nitrogen has been identified as a contaminant of concern in the local management plan under WAC 246-272A-0015;
(f) Not use disinfection to achieve fecal coliform or E. coli requirements in Table X of this section to meet:
1. (i) Treatment level BL1 or BL2 with less than 18 inches of vertical separation; or
2. (ii) Treatment level BL1 or BL2 in type 1 soils; or
3. (iii) Treatment level BL3.
(g) Minimize impact of phosphorus discharge in areas where the local health officer has identified phosphorus as a contaminant of concern in the local management plan under WAC 246-272A-0015;
(h) Locate and design repairs meeting the requirements in Table X of this section if the effluent treatment and soil dispersal component to be repaired or replaced is closer to any surface water, well, or spring than prescribed by the minimum separation required in Table IV of WAC 246-272A-0210(1);
(i) Design any nonconforming OSS using pressure distribution with timed dosing in the soil dispersal component; and

(j) Meet all other design requirements of this chapter to the maximum extent permitted by the site, to maximize the:

(i) Vertical separation;
(ii) Distance from a well or spring; and

(iii) Distance to surface water.

Table X

Treatment Component Performance Levels for Repair of OSS Not Meeting Vertical and Horizontal Separations¹

Horizontal Separation²

< 30 feet

≥ 30 < 50 feet

≥ 50 < 100 feet³

≥ 100 feet

Vertical Separation(in inches)

Soil Type

3-6

< 12

A & BL1

B & BL2

≥ 12 < 18

A & BL1

B & BL2

A & BL1

B & BL2

≥ 18 < 24

A & BL1

B & BL2

A & BL1

B & BL2

Conforming

≥ 24 < 36

A & BL1

B & BL2

C & BL3

OSS

≥ 36

A & BL1

B & BL2

C & BL3

B & BL2

C & BL3

¹	The treatment component performance levels correspond with those established for treatment components under the product performance testing requirements in Table III in WAC 246-272A-0110.
²	The horizontal separation indicated in Table X of this section is the distance between the soil dispersal component and the surface water, well, or spring. If the soil dispersal component is up-gradient of a surface water, well, or spring to be used as a potable water source, or beach where shellfish are harvested, the next higher treatment level shall apply unless treatment level A and BL1 is already required.
³	On a site where there is a horizontal setback of 75-100 feet between an OSS dispersal component and an individual water well, individual spring, nonmarine surface water or surface water that is not a public water source and a vertical separation of greater than 12 inches, a conforming OSS that complies with WAC 246-272A-0210(4) shall be installed if feasible.

[Statutory Authority: RCW 43.20.050(3), 43.20.065, chapters 70A.105 and 70A.110 RCW. WSR 24-06-046, § 246-272A-0280, filed 3/1/24, effective 4/1/25. Statutory Authority: RCW 43.20.050. WSR 05-15-119, § 246-272A-0280, filed 7/18/05, effective 7/1/07.]