OAR 635-420-0040: Minimum Standards for Covering or Containment

(1) All conveyances for chemical processing solutions shall be covered or contained to preclude access by wildlife. Conveyances for associated wastewaters shall be covered or contained to preclude access by wildlife, or shall be maintained in a condition that is not harmful to wildlife. (2) All uncontained chemical processing solution ponds or impoundments shall be covered to preclude access by wildlife. (3) Covers and containers shall preclude access to chemical processing solutions and associated wastewaters by wildlife. At a minimum, cover designs shall be based on the following factors: (a) Wind and snow loads at a mean recurrence interval of 100 years; (b) Size, shape and location of the area to be covered; (c) Species and behavior of wildlife at the mine site; (d) Direction of prevailing winds. (4) All covers, as well as their supports and attachments, shall be made of durable ultraviolet resistant materials. (5) The mesh openings of netting and other permeable covers shall be no larger than one square inch unless the Department determines that a larger mesh size is adequate to exclude birds, bats and other wildlife. (6) Netting and netting support systems shall meet the following minimum specifications: (a) Netting shall be solid-strand polypropylene, high density polyethylene or other material of equivalent or better strength, durability and resistance to penetration by wildlife; (b) Netting shall be black or another color which does not attract resident or migratory birds and bats; (c) Support cable shall be coated to minimize net abrasion; (d) Sections of netting shall be fastened together or terminated on cables in a manner which precludes access to processing solutions by wildlife. The following minimum specifications shall apply: (A) Where sections of netting are fastened together, they shall be overlapped a minimum of six inches and attached at intervals no greater than six inches; (B) Where a section of netting is terminated on a support cable or a perimeter ground cable, the netting shall be folded around the cable, overlap itself a minimum of six inches, and be attached to itself at intervals no greater than six inches; (C) Where sections of netting that are terminated on support cables lie adjacent to one another, the support cables shall be fastened together at intervals sufficient to prevent gaps greater than one inch wide between the support cables; (D) Rope made of polypropylene or other material of equivalent or better strength, durability and ultraviolet resistance shall be strung above the netting to minimize net ship in high winds; (E) Netting shall be fastened to perimeter ground cables which are securely anchored to the ground.