(a) Water quality performance standards: The post-development non-point source pollution runoff load shall not exceed the calculated pre-development load based upon the average land cover condition or the existing site condition. Compliance with the water quality performance standards shall be achieved by applying Performance-based water quality criteria in accordance with the Handbook.

(b) Water quantity performance standards: The post-development runoff rate shall not exceed the calculated pre-development runoff rate. When complying with subdivision 19 of 4 VAC 50-30-40, also known as “Minimum Standard 19”, to protect properties and receiving waterways downstream of land development projects, the twenty-four hour extended-detention of the runoff from the one-year frequency storm shall be used in lieu of the two-year storm.

(Ord. No. 06-17, 7/18/06)