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Virginia Administrative Code (Last Updated: January 10, 2017) |
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Title 12. Health |
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Agency 5. Department of Health |
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Chapter 590. Waterworks Regulations |
Section 970. Removal of volatile synthetic organic chemicals (VOCs)
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Appropriate processes or technologies (either specified as BAT in Appendix N or a division-approved alternative, such as other aeration techniques) that treat all the water in the waterworks shall be applied to achieve compliance. The selected design is to be supported by pilot studies unless at least two pilot studies, or two prototype plants, have demonstrated that the selected design is feasible. Such studies or prototypes shall be for waters having characteristics similar to the water that is to be treated.
A. Granular Activated Carbon (GAC). As in taste and odor control, GAC units may be used with appropriate pretreatment described in 12VAC5-590-870 B. The elements of a GAC system include carbon contactors, a carbon storage and transfer system, a regeneration system and a control system.
The selected GAC shall meet AWWA Standards. Multiple units shall be provided to process at least the peak day flow rate with one unit out of service. As carbon is corrosive, the use of noncorrosive piping and storage materials is mandatory.
B. Packed tower aeration. (Also see 12VAC5-590-910.)
1. Usually more efficient than other types of waterfall (natural) aeration.
2. With one unit out of service, the remaining unit(s) must be capable of handling peak day flows.
Historical Notes
Derived from VR355-18-009.13 § 3.34, eff. August 1, 1991; amended, Volume 09, Issue 17, eff. June 23, 1993; Volume 12, Issue 02, eff. November 15, 1995.