Or. Admin. R. 340-073-0041 - Filter Fabric

Except as otherwise allowed by the department, filter fabric used as a barrier between the lower lens of drain media and the medium sand in a conventional sand filter system must meet the following specifications:

(1) Material synthetic fabric, either spunbonded or woven.
(2) Burst strength not less than 25 psi.
(3) Air permeability not less than 500 cfm per sq. ft.
(4) Water flow rate not less than 500 gpm per sq. ft. at 3 inches of head.
(5) Hydrophilic surface reaction to water.
(6) Equivalent opening size of 70 to 100 sieve.
(7) Chemical properties:
(a) Nonbiodegradable.
(b) Resistant to acids and alkalies within a pH range of 4 to 10.
(c) Resistant to common solvents.


Or. Admin. R. 340-073-0041
DEQ 15-1986, f. & ef. 8-6-86; DEQ 11-2004, f. 12-22-04, cert. ef. 3-1-05

Stat. Auth.: ORS 454.625 & 468.020

Stats. Implemented: ORS 454.615

State regulations are updated quarterly; we currently have two versions available. Below is a comparison between our most recent version and the prior quarterly release. More comparison features will be added as we have more versions to compare.

No prior version found.