15A NCAC 18C .0712      DIRECT FILTRATION

Water treatment plants which use direct filtration may be approved to treat high quality source waters derived from uninhibited watersheds classified WS-I.  A proposal, including an engineering report as described in Rule .0710 Item (1) of this Section shall be submitted to the Department.

(1)           The following raw water maximum contaminant concentrations shall be met:  Turbidity - 5 NTU, coliform - 500/100 ml, fecal coliform - 50/100 ml, color - 15 CU.  Fluctuations shall not exceed 5 percent per hour.

(2)           A minimum of 5 days off-stream storage shall be provided except in cases where the source waters are derived from in-stream impoundments and it is demonstrated that the raw water quality standards and fluctuations or Item (1) of this Rule are maintained at the entrance to the water treatment plant.

(3)           If the Department determines that the proposed water treatment plant provides treatment techniques that are consistent with this Subchapter and that the treatment is feasible for the source water, a pilot plant study shall be conducted in accordance with Rule .0714 of this Section.

(4)           If the pilot study demonstrates to the Department that the proposed plant can consistently produce water which complies with all requirements of this Subchapter, detailed engineering plans and specifications for the proposed plant and appurtenances shall be presented to the Department for review and approval prior to construction or letting a contract.

History Note:        Authority G.S. 130A-315; 130A-317; P.L. 93-523;

Eff. July 1, 1994;

Pursuant to G.S. 150B-21.3A, rule is necessary without substantive public interest Eff. November 23, 2015.