Section 50. Water quality modeling

Water quality models may be required to predict the effect of wastewater discharges on the water quality of the receiving waterbody, the embayment, and the Potomac River. The purpose of the modeling shall be to determine if more stringent limits than those required in 9VAC25-415-40 are required to meet water quality standards. If modeling demonstrates the necessity for more restrictive limits, the more restrictive limits shall apply. Where needed, modeling shall account for and address previous modeling exercises and shall include all relevant point and nonpoint sources. All models shall undergo a peer review process. The models and modeling results shall be considered during the public participation process to ensure proper public input into the modeling process. The models shall be documented and certified by the Virginia Department of Environmental Quality for use in preparing VPDES permits for discharges to the Potomac Embayments and the Potomac River. All changes and modifications to the models shall receive peer review and be appropriately documented. Documentation on the models shall include the basis and reasoning for the recommended models including inputs and assumptions. The rationale shall be described in nontechnical language so someone who is reasonably familiar with water pollution problems can understand the inputs and the reasons behind them.

Historical Notes

Derived from Volume 13, Issue 12, eff. April 2, 1997.

Statutory Authority

§ 62.1-44.15 of the Code of Virginia.