TITLE 9. ENVIRONMENT

STATE WATER CONTROL BOARD

Final Regulation

Title of Regulation: 9VAC25-820. General Virginia Pollutant Discharge Elimination System (VPDES) Watershed Permit Regulation for Total Nitrogen and Total Phosphorus Discharges and Nutrient Trading in the Chesapeake Bay Watershed in Virginia (amending 9VAC25-820-10, 9VAC25-820-20).

Statutory Authority: § 62.1-44.15 of the Code of Virginia; § 402 of the Clean Water Act; 40 CFR Parts 122, 123, and 124.

Effective Date: November 9, 2022.

Agency Contact: Allan Brockenbrough, Department of Environmental Quality, 1111 East Main Street, Suite 1400, P.O. Box 1105, Richmond, VA 23218, telephone (804) 836-2321, FAX (804) 698-4178, or email allan.brockenbrough@deq.virginia.gov.

Summary:

Pursuant to Chapter 356 of the 2022 Acts of Assembly, the amendments conform the regulation to a statutorily change shifting authority to issue and enforce permits from the State Water Control Board to the Department of Environmental Quality.

9VAC25-820-10. Definitions.

Except as defined below, the words and terms used in this chapter shall have the meanings defined in the Virginia Pollutant Discharge Elimination System (VPDES) Permit Regulation (9VAC25-31).

"Annual mass load of total nitrogen" (expressed in pounds per year) means the sum of the total monthly loads for all of the months in one calendar year. See Part I E 4 of the general permit in 9VAC25-820-70 for calculating total monthly load.

"Annual mass load of total phosphorus" (expressed in pounds per year) means the sum of the total monthly loads for all of the months in one calendar year. See Part I E 4 of the general permit in 9VAC25-820-70 for calculating total monthly load.

"Association" means the Virginia Nutrient Credit Exchange Association authorized by § 62.1-44.19:17 of the Code of Virginia.

"Attenuation" means the rate at which nutrients are reduced through natural processes during transport in water.

"Board" means the Virginia State Water Control Board or State Water Control Board. When used outside the context of the promulgation of regulations, including regulations to establish general permits, "board" means the Department of Environmental Quality.

"Delivered total nitrogen load" means the discharged mass load of total nitrogen from a point source that is adjusted by the delivery factor for that point source.

"Delivered total phosphorus load" means the discharged mass load of total phosphorus from a point source that is adjusted by the delivery factor for that point source.

"Delivery factor" means an estimate of the number of pounds of total nitrogen or total phosphorus delivered to tidal waters for every pound discharged from a facility, as determined by the specific geographic location of the facility, to account for attenuation that occurs during riverine transport between the facility and tidal waters. Delivery factors shall be calculated using the Chesapeake Bay Program watershed model. For the purpose of this regulation, delivery factors with a value greater than 1.00 in the Chesapeake Bay Program watershed model shall be considered to be equal to 1.00.

"Department" or "DEQ" means the Department of Environmental Quality.

"Director" means the director of the Department of Environmental Quality.

"Eastern Shore trading ratio" means the ratio of pounds of point source credits from another tributary that can be acquired and applied by the owner of a facility in the Eastern Shore Basin for every pound of point source total nitrogen or total phosphorus discharged from the Eastern Shore Basin facility. Trading ratios are expressed in the form "credits supplied: credits received."

"Equivalent load" means:

2,300 pounds per year of total nitrogen or 300 pounds per year of total phosphorus discharged by an industrial facility are considered equivalent to the load discharged from sewage treatment works with a design capacity of 0.04 million gallons per day,

5,700 pounds per year of total nitrogen or 760 pounds per year of total phosphorus discharged by an industrial facility are considered equivalent to the load discharged from sewage treatment works with a design capacity of 0.1 million gallons per day, and

28,500 pounds per year of total nitrogen or 3,800 pounds per year of total phosphorus discharged by an industrial facility are considered equivalent to the load discharged from sewage treatment works with a design capacity of 0.5 million gallons per day.

"Existing facility" means a facility (i) subject to a current individual VPDES permit from which a discharge has commenced or for which its owner has received a Certificate to Construct (for sewage treatment works, or equivalent DEQ approval for discharges from industrial facilities) for the treatment works used to derive its wasteload allocation on or before July 1, 2005, or (ii) for which the owner has a wasteload allocation listed in 9VAC25-720-50 C, 9VAC25-720-60 C, 9VAC25-720-70 C, 9VAC25-720-110 C, and 9VAC25-720-120 C of the Water Quality Management Planning Regulation. Existing facility shall also mean and include any facility, not subject to an individual VPDES permit, for which its owner holds a separate wasteload allocation in 9VAC25-720-120 C of the Water Quality Management Planning Regulation.

"Expansion" or "expands" means (i) initiating construction at an existing treatment works after July 1, 2005, to increase design flow capacity, except that the term does not apply in those cases where a Certificate to Construct (for sewage treatment works, or equivalent DEQ approval for discharges from industrial facilities) was issued on or before July 1, 2005, or (ii) industrial production process changes or the use of new treatment products at industrial facilities that increase the annual mass load of total nitrogen or total phosphorus above the wasteload allocation.

"Facility" means a point source from which a discharge or proposed discharge of total nitrogen or total phosphorus to the Chesapeake Bay or its tributaries exists. This term does not include confined animal feeding operations, discharges of storm water, return flows from irrigated agriculture, or vessels.

"General permit" means this general permit authorized by § 62.1-44.19:14 of the Code of Virginia.

"Industrial facility" means any facility (as defined above) other than sewage treatment works.

"Local water quality-based limitations" means limitations intended to protect local water quality including applicable total maximum daily load (TMDL) allocations, applicable Virginia Pollution Discharge Elimination System (VPDES) permit limits, applicable limitations set forth in water quality standards established under § 62.1-44.15 (3a) of the Code of Virginia, or other limitations as established by the State Water Control Board.

"New discharge" means any discharge from a facility that did not commence prior to July 1, 2005, except that the term does not apply in those cases where a Certificate to Construct (for sewage treatment works, or equivalent DEQ approval for discharges from industrial facilities) was issued to the facility on or before July 1, 2005.

"Nonsignificant discharger" means (i) a sewage treatment works discharging to the Chesapeake Bay watershed downstream of the fall line with a design capacity of less than 0.1 million gallons per day, or less than an equivalent load discharged from industrial facilities, or (ii) a sewage treatment works discharging to the Chesapeake Bay watershed upstream of the fall line with a design capacity of less than 0.5 million gallons per day, or less than an equivalent load discharged from industrial facilities.

"Offset" means to acquire an annual wasteload allocation of total nitrogen or total phosphorus for a new or expanding facility to ensure that there is no net increase of nutrients into the affected tributary of the Chesapeake Bay.

"Permitted design capacity" or "permitted capacity" means the allowable load (pounds per year) assigned to an existing facility that is a nonsignificant discharger and that does not have a wasteload allocation listed in 9VAC25-720-50 C, 9VAC25-720-60 C, 9VAC25-720-70 C, 9VAC25-720-110 C, and 9VAC25-720-120 C of the Water Quality Management Planning Regulation. The permitted design capacity is calculated based on the design flow and installed nutrient removal technology (for sewage treatment works, or equivalent discharge from industrial facilities) at a facility that has either commenced discharge, or for which an owner has received a Certificate to Construct (for sewage treatment works, or equivalent DEQ approval for discharges from industrial facilities) prior to July 1, 2005. This mass load is used for (i) determining whether the owner of the expanding facility must offset additional mass loading of nitrogen and phosphorus and (ii) determining whether the owner of the facility must acquire credits at the end of a calendar year. For the purpose of this chapter, owners of facilities that have installed secondary wastewater treatment (intended to achieve BOD and TSS monthly average concentrations equal to or less than 30 milligrams per liter) are assumed to achieve an annual average total nitrogen effluent concentration of 18.7 milligrams per liter and an annual average total phosphorus effluent concentration of 2.5 milligrams per liter. Permitted design capacities for facilities that, before July 1, 2005, were required to comply with more stringent nutrient limits shall be calculated using the more stringent values.

"Permitted facility" means a facility whose owner is authorized by this general permit to discharge total nitrogen or total phosphorus. For the sole purpose of generating point source nitrogen credits or point source phosphorus credits, "permitted facility" shall also mean the Blue Plains wastewater treatment facility operated by the District of Columbia Water and Sewer Authority.

"Permittee" means a person authorized by this general permit to discharge total nitrogen or total phosphorus.

"Point source nitrogen credit" means the difference between (i) the wasteload allocation for a permitted facility specified as an annual mass load of total nitrogen and (ii) the monitored annual mass load of total nitrogen discharged from that facility, where clause (ii) is less than clause (i), and where the difference is adjusted by the applicable delivery factor and expressed as pounds per year of delivered total nitrogen load.

"Point source phosphorus credit" means the difference between (i) the wasteload allocation for a permitted facility specified as an annual mass load of total phosphorus and (ii) the monitored annual mass load of total phosphorus discharged from that facility, where clause (ii) is less than clause (i), and where the difference is adjusted by the applicable delivery factor and expressed as pounds per year of delivered total phosphorus load.

"Quantification level" or "QL" means the minimum levels, concentrations, or quantities of a target variable (e.g., target analyte) that can be reported with a specified degree of confidence in accordance with 1VAC30-45, Certification for Noncommercial Environmental Laboratories, or 1VAC30-46, Accreditation for Commercial Environmental Laboratories.

"Registration list" means a list maintained by the department indicating all facilities that are registered for coverage under this general permit, by tributary, including their wasteload allocations, permitted design capacities, and delivery factors as appropriate.

"Significant discharger" means the owner of (i) a sewage treatment works discharging to the Chesapeake Bay watershed upstream of the fall line with a design capacity of 0.5 million gallons per day or greater, or an equivalent load discharged from industrial facilities; (ii) a sewage treatment works discharging to the Chesapeake Bay watershed downstream of the fall line with a design capacity of 0.1 million gallons per day or greater, or an equivalent load discharged from industrial facilities; (iii) a planned or newly expanding sewage treatment works discharging to the Chesapeake Bay watershed upstream of the fall line that was expected to be in operation by December 31, 2010, with a permitted design of 0.5 million gallons per day or greater, or an equivalent load to be discharged from industrial facilities; or (iv) a planned or newly expanding sewage treatment works discharging to the Chesapeake Bay watershed downstream of the fall line that was expected to be in operation by December 31, 2010, with a design capacity of 0.1 million gallons per day or greater, or an equivalent load to be discharged from industrial facilities.

"State-of-the-art nutrient removal technology" means (i) technology that will achieve an annual average total nitrogen effluent concentration of three milligrams per liter and an annual average total phosphorus effluent concentration of 0.3 milligrams per liter or (ii) equivalent load reductions in total nitrogen and total phosphorus through recycle or reuse of wastewater as determined by the department.

"Tributaries" means those river basins listed in the Chesapeake Bay TMDL and includes the Potomac, Rappahannock, York, and James River Basins and the Eastern Shore Basin, which encompasses the creeks and rivers of the Eastern Shore of Virginia that are west of Route 13 and drain into the Chesapeake Bay.

"VPDES" means Virginia Pollutant Discharge Elimination System.

"Wasteload allocation" means the most limiting of (i) the water quality-based annual mass load of total nitrogen or annual mass load of total phosphorus allocated to individual facilities pursuant to 9VAC25-720-50 C, 9VAC25-720-60 C, 9VAC25-720-70 C, 9VAC25-720-110 C, and 9VAC25-720-120 C of the Water Quality Management Planning Regulation or its successor, or permitted capacity in the case of nonsignificant dischargers; (ii) the water quality-based annual mass load of total nitrogen or annual mass load of total phosphorus acquired pursuant to § 62.1-44.19:15 of the Code of Virginia for new or expanded facilities; or (iii) applicable total nitrogen or total phosphorus wasteload allocations under the Chesapeake Bay total maximum daily loads (TMDLs) to restore or protect the water quality and beneficial uses of the Chesapeake Bay or its tidal tributaries.

9VAC25-820-20. Purpose, applicability, delegation of authority.

A. This regulation fulfills the statutory requirement for the General VPDES Watershed Permit for Total Nitrogen and Total Phosphorus discharges and nutrient trading in the Chesapeake Bay watershed issued by the board pursuant to the Clean Water Act (33 USC § 1251 et seq.) and § 62.1-44.19:14 of the Code of Virginia.

B. This general permit regulation governs owners of facilities holding individual VPDES permits or otherwise meeting the definition of "existing facility" that discharge or propose to discharge total nitrogen or total phosphorus to the Chesapeake Bay or its tributaries.

C. The director may perform any act of the board provided under this regulation, except as limited by § 62.1-44.14 of the Code of Virginia.