{"data":{"id":"us-va/9vac25-260-110","jurisdiction":"us-va","citation":"9VAC25-260-110","heading":"Halogen ban","body":"A. Chlorine or other halogen compounds Bromine, bromine chloride, hypochlorite and chlorine dioxide. shall not be used for disinfection purposes or other treatment purposes including biocide applications for any treatment facility with a permitted flow of 20,000 gallons per day or more discharging to waters containing endangered or threatened species listed in subsection C of this section or to waters listed as i and ii in the River Basin Section Tables, 9VAC25-260-390 et seq. except for dischargers who intermittently chlorinate. Dischargers of less than 20,000 gallons per day shall dechlorinate to the requirements of the numerical chlorine criteria in 9VAC25-260-140 B or to a nondetectable chlorine residual. Dischargers who intermittently chlorinate (not more than two hours in any eight-hour period) shall be required to install equipment or employ procedures, or both, to ensure dechlorination to a chlorine residual that meets the numerical chlorine criteria in 9VAC25-260-140 B, and to apply effective best management practices for chlorine. Dischargers who intermittently chlorinate shall, in order to address a possible malfunction of the dechlorination system, either have storage sufficient to contain the chlorinated water until it can be dechlorinated prior to discharge or have an online redundant and operational back-up dechlorination system.\n\nB. Variance to this requirement shall not be made unless it has been affirmatively demonstrated that the existing uses of the water will be maintained and that either a change is justifiable to provide necessary economic or social development or the degree of waste treatment necessary to preserve the existing quality cannot be economically or socially justified.\n\nC. TENNESSEE AND BIG SANDY RIVER BASINS\n\nCLINCH RIVER SUBBASIN\n\nPowell River from river mile 136 (south of Jonesville) downstream to the Tennessee/Virginia line (river mile 115.8—total 20.2 miles).\n\nEndangered Species:\n\nAppalachian monkeyface pearly mussel\n\nQuadrula sparsa\n\nBirdwing pearly mussel\n\nConradilla caelata\n\nCumberland monkeyface pearly mussel\n\nQuadrula intermedia\n\nDromedary pearly mussel\n\nDromus dromas\n\nFine-rayed pigtoe pearly mussel\n\nFusconaia cuneolus\n\nShiny pigtoe pearly mussel\n\nFusconaia edgariana\n\nThreatened Species:\n\nSlender chub\n\nHybopsis cahni\n\nYellowfin madtom\n\nNoturus flavipinnis\n\nClinch River from river mile 323 (Richlands) downstream to the Tennessee/Virginia line (river mile 202.1).\n\nEndangered Species:\n\nAppalachian monkeyface pearly mussel\n\nQuadrula sparsa\n\nBirdwing pearly mussel\n\nConradilla caelata\n\nFine-rayed pigtoe pearly mussel\n\nFusconaia cuneolus\n\nGreen blossom pearly mussel\n\nDysnomia torulosa gubernaculum\n\nPink mucket pearly mussel\n\nLampsilis orbiculata\n\nShiny pigtoe pearly mussel\n\nFusconaia edgariana\n\nClinch River from the Scott/Russell County line (at Bangor—river mile 244.2) downstream to the Tennessee boundary (river mile 202.1).\n\nThreatened Species:\n\nSlender chub\n\nHybopsis cahni\n\nCopper Creek from 2 miles above its confluence with the Clinch River (river mile 211.6).\n\nEndangered Species:\n\nFine-rayed pigtoe pearly mussel\n\nFusconaia cuneolus\n\nShiny pigtoe pearly mussel\n\nFusconaia edgariana\n\nCopper Creek from Dickensville (river mile 56) in Russell County downstream to its confluence with the Clinch River.\n\nThreatened Species:\n\nYellowfin madtom\n\nNoturus flavipinnis\n\nHOLSTON RIVER SUBBASIN\n\nNorth Fork Holston River from river mile 93.3 (near Broadford) downstream to the Smyth/Washington County line (river mile 82.1).\n\nEndangered Species:\n\nShiny pigtoe pearly mussel\n\nFusconaia edgariana\n\nNorth Fork Holston River from the Smyth/Washington County line (river mile 82.1) to the Tennessee/Virginia boundary (river mile 5).\n\nThreatened Species:\n\nSpotfin chub\n\nHybopsis monacha\n\nMiddle Fork Holston River from river mile 43 (in Marion) downstream to river mile 18.4.\n\nEndangered Species:\n\nTan riffle shell mussel\n\nDysnomia walkeri\n\nMiddle Fork Holston River from river mile 6.5 to river mile 3.2 near Osceola.\n\nThreatened Species:\n\nSpotfin chub\n\nHybopsis monacha","path":["Title 9. Environment","Agency 25. State Water Control Board","Chapter 260. Water Quality Standards","Part I. Surface Water Standards with General, Statewide Application"],"source_url":"https://law.lis.virginia.gov/admincode/title9/agency25/chapter260/section110/","current_through":"2026 Regular Session (effective July 1, 2026)","vintage":"","retrieved_at":"2026-09-14T04:49:14Z","sha256":"26970c642dd261f4fdd5eca65645006d3d098cb35af816da4c014dffdbf2925f","source_id":"us-va-vac","stale":false,"prev":"us-va/9vac25-260-100","next":"us-va/9vac25-260-140"},"notice":"GroundRules: Original legal text. Not legal advice."}