A. Land-disturbing activities that meet one of the criteria in this subsection are regulated as follows:

1. Land-disturbing activity that disturbs 10,000 square feet or more, although the locality may reduce this regulatory threshold to a smaller area of disturbed land, is less than one acre, not in an area of a locality designated as a Chesapeake Bay Preservation Area, and not part of a common plan of development or sale, is subject to criteria defined in Article 2 (9VAC25-875-540 et seq.) of Part V (9VAC25-875-470 et seq.) of this chapter.

2. Land-disturbing activity that disturbs 2,500 square feet or more, although the locality may reduce this regulatory threshold to a smaller area of disturbed land, is less than one acre, and in an area of a locality designated as a Chesapeake Bay Preservation Area is subject to criteria defined in Article 2 and Article 3 5 (9VAC25-875-570 9VAC25-875-740 et seq.) of Part V unless Article 4 (9VAC25-875-670 et seq.) of Part V of this chapter is applicable, as determined in accordance with 9VAC25-875-480 and 9VAC25-875-490. For land-disturbing activities for single-family detached residential structures, Article 2 of Part V and water quantity technical criteria, 9VAC25-875-600, shall apply to any land-disturbing activity that disturbs 2,500 square feet or more of land, and the locality also may require compliance with the water quality technical criteria, 9VAC25-875-580 and 9VAC25-875-590.

3. Land-disturbing activity that disturbs less than one acre, but is part of a larger common plan of development or sale that disturbs one acre or more, is subject to criteria defined in Article 2 and Article 3 of Part V unless Article 4 of Part V of this chapter is applicable, as determined in accordance with 9VAC25-875-480 and 9VAC25-875-490.

4. Land-disturbing activity that disturbs one acre or more is subject to criteria defined in Article 2 and Article 3 of Part V unless Article 4 of Part V is applicable, as determined in accordance with 9VAC25-875-480 and 9VAC25-875-490.

B. A locality may, by local ordinance adopted pursuant to § 62.1-44.15:33 or 62.1-44.15:65 of the Code of Virginia, adopt more stringent local requirements.

A. Land-disturbing activities that meet one of the criteria in this subsection are regulated as follows:

1. Land-disturbing activity that disturbs 10,000 square feet or more, although the locality may reduce this regulatory threshold to a smaller area of disturbed land, is less than one acre, and not in an area of a locality designated as a Chesapeake Bay Preservation Area is subject to criteria defined in Article 2 (9VAC25-875-540 et seq.) of Part V (9VAC25-875-470 et seq.) of this chapter.

2. Land-disturbing activity that disturbs 2,500 square feet or more, although the locality may reduce this regulatory threshold to a smaller area of disturbed land, is less than one acre, and in an area of a locality designated as a Chesapeake Bay Preservation Area is subject to criteria defined in Article 2 and Article 5 (9VAC25-875-740 et seq.) of Part V of this chapter.

B. A locality may, by local ordinance adopted pursuant to § 62.1-44.15:65 of the Code of Virginia, adopt more stringent local requirements.

Notwithstanding any other provisions of the Erosion and Sediment Control Law for Localities Not Administering a Virginia Erosion and Stormwater Management Program (ESCL), the following activities are not required to comply with the ESCL unless otherwise required by federal law:

1. Disturbance of a land area of less than 10,000 square feet in size or less than 2,500 square feet in an area designated as a Chesapeake Bay Preservation Area pursuant to the Chesapeake Bay Preservation Act (§ 62.1-44.15:67 et seq. of the Code of Virginia). However, the governing body of the program authority may reduce this exception to a smaller area of disturbed land or qualify the conditions under which this exception shall apply;

2. Minor land-disturbing activities such as home gardens and individual home landscaping, repairs, and maintenance work;

3. Installation, maintenance, or repair of any individual service connection;

4. Installation, maintenance, or repair of any underground utility line when such activity occurs on an existing hard surfaced road, street, or sidewalk, provided the land-disturbing activity is confined to the area of the road, street, or sidewalk that is hard surfaced;

5. Installation, maintenance, or repair of any septic tank line or drainage field unless included in an overall plan for land-disturbing activity relating to construction of the building to be served by the septic tank system;

6. Permitted surface or deep mining operations and projects or oil and gas operations and projects conducted pursuant to Title 45.2 of the Code of Virginia;

7. Clearing of lands specifically for bona fide agricultural purposes; the management, tilling, planting, or harvesting of agricultural, horticultural, or forest crops; livestock feedlot operations; agricultural engineering operations, including construction of terraces, terrace outlets, check dams, desilting basins, dikes, ponds, ditches, strip cropping, lister furrowing, contour cultivating, contour furrowing, land drainage, and land irrigation; or as additionally set forth by the board in regulations. However, this exception shall not apply to harvesting of forest crops unless the area on which harvesting occurs is reforested artificially or naturally in accordance with the provisions of Chapter 11 (§ 10.1-1100 et seq.) of Title 10.1 of the Code of Virginia or is converted to bona fide agricultural or improved pasture use as described in subsection B of § 10.1-1163 of the Code of Virginia;

8. Installation of fence and sign posts or telephone and electric poles and other kinds of posts or poles;

9. Shoreline erosion control projects on tidal waters when all of the land-disturbing activities are within the regulatory authority of and approved by local wetlands boards, the Virginia Marine Resources Commission, or the U.S. Army Corps of Engineers; however, any associated land that is disturbed outside of this exempted area shall remain subject to the ESCL and the regulations adopted pursuant thereto this chapter;

10. Land-disturbing activities in response to a public emergency where the related work requires immediate authorization to avoid imminent endangerment to human health or the environment. In such situations, the VESCP authority shall be advised of the disturbance within seven days of commencing the land-disturbing activity, and compliance with the administrative requirements of Article 2 (9VAC25-875-540 et seq.) of Part V (9VAC25-875-470 et seq.) of this chapter is required within 30 days of commencing the land-disturbing activity;

11. Discharges to a sanitary sewer or a combined sewer system that are not from a land-disturbing activity; and

12. Repair or rebuilding of the tracks, rights-of-way, bridges, communication facilities, and other related structures and facilities of a railroad company.

A. The VESCP authority shall review erosion and sediment control plans prepared in accordance with 9VAC25-875-550 that detail the criteria, techniques, and methods as defined in 9VAC25-875-550 for land-disturbing activities described in 9VAC25-875-560. Activities not required to comply with VESCL are defined in 9VAC25-875-280.

B. When determined that the plan meets the minimum criteria, techniques, and methods as defined in 9VAC25-875-550 9VAC25-875-560, the VESCP authority shall review erosion and sediment control plans submitted and grant written approval within 60 days of the receipt of the plan.

C. When the VESCP authority determines a plan is inadequate, written notice stating the specific reasons for disapproval shall be communicated to the applicant within 45 days. The notice shall specify the modifications, terms, and conditions that are necessary for approval of the plan. If no action is taken by the VESCP authority within 45 days, the plan shall be deemed approved and the proposed activity authorized. The VESCP authority shall act on any erosion and sediment control plan that has been previously deemed inadequate within 45 days after receipt of a revised plan if deemed adequate.

D. For sites requiring coverage under the General VPDES Permit for Discharges of Stormwater from Construction Activities, the VESCP authority shall obtain evidence of such coverage prior to approving the erosion and sediment control plan.

E. The person responsible for carrying out the plan shall provide the name of an individual holding a certificate to the VESCP authority who will be in charge of and responsible for carrying out the land-disturbing activity. However, the VESCP authority may waive the Responsible Land Disturber Certificate requirement for an agreement in lieu of a plan in accordance with § 62.1-44.15:55 of the Code of Virginia.

F. The VESCP authority may require approval of an erosion and sediment control plan for any land identified as an erosion impact area in accordance with § 62.1-44.15.55 of the Code of Virginia.

G. All erosion and sediment control structures and systems shall be maintained, inspected, and repaired as needed to ensure continued performance of their intended function. A statement describing the maintenance responsibilities of the individual responsible for carrying out the land-disturbing activity shall be included in the approved erosion and sediment control plan.

A. This section sets forth the criteria that will be used by the department to determine whether a locality operating a VESCP under authority of the ESCL, a "VESCP authority," satisfies minimum standards of effectiveness, as follows.

Each VESCP must contain an ordinance or other appropriate document adopted by the VESCP authority. Such document must be consistent with the ESCL and Part III (9VAC25-875-210 et seq.) of this chapter, including the following criteria:

1. The document shall include or reference the definition of land-disturbing activity, including exemptions as well as any other significant terms, as necessary to produce an effective VESCP;

2. The document shall identify the VESCP authority and any soil and water conservation district, adjacent locality, or other public or private entities that the VESCP authority entered into agreements or contracts with to assist with carrying out the provisions of the ESCL and Part III of this chapter and must include the requirements and design standards to be used in the program;

3. The document shall include procedures for submission and approval of plans, issuance of permits, monitoring and inspections of land-disturbing activities. The position, agency, department, or other party responsible for conducting inspections shall be identified. The VESCP authority shall maintain, either onsite or in VESCP files, a copy of the approved plan and a record of inspections for each active land-disturbing activity;

4. Each VESCP operated by a county, city, or town shall include provisions for the integration of the VESCP with flood insurance, flood plain management, and other programs requiring compliance prior to authorizing a land-disturbing activity in order to make the submission and approval of plans, payment of fees, and coordination of inspection and enforcement activities more convenient and efficient both for the local governments and those responsible for compliance with the programs; and

5. The VESCP authority must take appropriate enforcement actions, where authorized to do so, to achieve compliance with the program and maintain a record of enforcement actions for all active land-disturbing activities.

B. The department shall periodically conduct a comprehensive review and evaluation of each VESCP authority pursuant to subdivision (19) of § 62.1-44.15 of the Code of Virginia. The department will coordinate the review with its other program reviews for the same entity to avoid redundancy. The review and evaluation of a VESCP authority shall consist of the following: (i) consultation with the local program administrator or designee; (ii) review of the local ordinance and other applicable documents; (iii) review of plans approved by the VESCP authority; (iv) inspection of regulated activities; and (v) review of enforcement actions where authorized to do so. The department is also authorized to conduct a partial VESCP compliance review.

C. Each VESCP authority shall be reviewed and evaluated by the department for effectiveness in carrying out the ESCL and Part III of this chapter using the criteria in this section.

D. If deficiencies noted in the review will cause the VESCP to be inconsistent with the ESCL or this chapter, the department shall provide the VESCP authority with a copy of the department's decision that specifies the deficiencies, action needed to be taken, and an approved corrective action plan and schedule required to attain the minimum standard of effectiveness. If the VESCP authority has not implemented the necessary compliance actions identified by the department within the corrective action schedule, or such additional period as is granted to complete the implementation of the corrective action, then the department shall have the authority to (i) issue a special order to any VESCP authority imposing a civil penalty set out in § 62.1-44.15 of the Code of Virginia or (ii) revoke its approval of the VESCP fails to bring its program into compliance in accordance with the compliance schedule, then the department is authorized to (i) issue a special order to any locality imposing a civil penalty not to exceed $5,000 per violation with the maximum amount not to exceed $50,000 per order for noncompliance with the state program, to be paid into the state treasury and deposited in the Stormwater Local Assistance Fund established in § 62.1-44.15:29.1 of the Code of Virginia or (ii) with the consent of the locality, provide in an order issued against the locality for the payment of civil charges for violations in lieu of civil penalties, in specific sums not to exceed the limit stated in this subdivision. The Administrative Process Act (§ 2.2-4000 et seq. of the Code of Virginia) and Article 5 (§ 62.1-44.20 et seq.) of Chapter 3.1 of Title 62.1 if the Code of Virginia shall govern the review activities and proceedings of the department and the judicial review thereof. In lieu of issuing a special order or revoking the program, the department is authorized to take legal action against a VESCP authority to ensure compliance.

E. Review and evaluation of VESCPs shall be conducted according to a schedule adopted by the department in accordance with subdivision (19) of § 62.1-44.15 of the Code of Virginia.

A. Land-disturbing activities that meet one of the criteria in this subsection are regulated as follows:

1. Land-disturbing activity that disturbs 10,000 square feet or more, although a locality may reduce this regulatory threshold to a smaller area of disturbed land, is less than one acre, not in an area of a locality designated as a Chesapeake Bay Preservation Area, and not part of a common plan of development or sale, is subject to criteria defined in Article 2 (9VAC25-875-540 et seq.) of this part of this chapter.

2. Land-disturbing activity that disturbs 2,500 square feet or more, although a locality may reduce this regulatory threshold to a smaller area of disturbed land, is less than one acre, and in an area of a locality designated as a Chesapeake Bay Preservation Area is subject to criteria defined in Article 2 and Article 3 5 (9VAC25-875-570 9VAC25-875-740 et seq.) of this part unless Article 4 (9VAC25-875-670 et seq.) of this part is applicable, as determined in accordance with 9VAC25-875-480 and 9VAC25-875-490. For land-disturbing activities for single-family detached residential structures, Article 2 of this part and water quantity technical criteria, 9VAC25-875-600, shall apply to any land-disturbing activity that disturbs 2,500 square feet or more of land, and the locality also may require compliance with the water quality technical criteria, 9VAC25-875-580 and 9VAC25-875-590.

3. Land-disturbing activity that disturbs less than one acre, but is part of a larger common plan of development or sale that disturbs one acre or more, is subject to criteria defined in Article 2 and Article 3 of this part unless Article 4 of this part is applicable, as determined in accordance with 9VAC25-875-480 and 9VAC25-875-490.

4. Land-disturbing activity that disturbs one acre or more is subject to criteria defined in Article 2 and Article 3 of this part unless Article 4 of this part is applicable, as determined in accordance with 9VAC25-875-480 and 9VAC25-875-490.

B. A locality may, by local ordinance adopted pursuant to § 62.1-44.15:33 or 62.1-44.15:65 of the Code of Virginia, adopt more stringent local requirements.

A. Any land-disturbing activity shall be considered grandfathered by the VESMP authority and shall be subject to the technical criteria of Article 4 (9VAC25-875-670 et seq.) of this part provided:

1. A proffered or conditional zoning plan, zoning with a plan of development, preliminary or final subdivision plat, preliminary or final site plan, or any document determined by the locality to be equivalent thereto (i) was approved by the locality prior to July 1, 2012; (ii) provided a layout as defined in 9VAC25-875-670; (iii) will comply with the technical criteria of Article 4 of this part; and (iv) has not been subsequently modified or amended in a manner resulting in an increase in the amount of phosphorus leaving each point of discharge and such that there is no increase in the volume or rate of runoff;

2. A permit has not been issued prior to July 1, 2014; and

3. Land disturbance did not commence prior to July 1, 2014.

B. Locality, state, and federal projects shall be considered grandfathered by the VESMP authority and shall be subject to the technical criteria of Article 4 of this part provided:

1. There has been an obligation of locality, state, or federal funding, in whole or in part, prior to July 1, 2012, or the department has approved a stormwater management plan prior to July 1, 2012;

2. A permit has not been issued prior to July 1, 2014; and

3. Land disturbance did not commence prior to July 1, 2014.

C. Land disturbing activities grandfathered under subsections A and B of this section shall remain subject to the technical criteria of Article 4 of this part for one additional permit cycle. After such time, portions of the project not under construction shall become subject to any new technical criteria adopted by the board.

D. B. In cases where governmental bonding or public debt financing has been issued for a project prior to July 1, 2012, such project shall be subject to the technical criteria of Article 4 of this part.

E. C. Nothing in this section shall preclude an operator from constructing to a more stringent standard at the operator's discretion.

A. A stormwater pollution prevention plan shall include an approved erosion and sediment control plan, an approved stormwater management plan, a pollution prevention plan for regulated land-disturbing activities, and a description of any additional control measures necessary to address a TMDL pursuant to subsection E of this section.

B. An erosion and sediment control plan consistent with the requirements of 9VAC25-875-550 and 9VAC25-875-560 must be designed and implemented during construction activities. Prior to land disturbance, this plan must be approved by the VESCP authority, VESMP authority, or the department.

C. A stormwater management plan consistent with the requirements of 9VAC25-875-510 must be designed and implemented during construction activities. Prior to land disturbance, this plan must be approved by the VESMP authority or the department.

D. A pollution prevention plan that identifies potential sources of pollutants that may reasonably be expected to affect the quality of stormwater discharges from the construction site and describe control measures that will be used to minimize pollutants in stormwater discharges from the construction site must be developed before land disturbance commences.

E. In addition to the requirements of subsections A through D of this section, if a specific wasteload allocation for a pollutant has been established in an approved TMDL and is assigned to stormwater discharges from a construction activity, additional control measures must be identified and implemented by the operator so that discharges are consistent with the assumptions and requirements of the wasteload allocation.

F. The stormwater pollution prevention plan (SWPPP) must address the following requirements as specified in 40 CFR 450.21, to the extent otherwise required by state law or regulations and any applicable requirements of a permit:

1. Control stormwater volume and velocity within the site to minimize soil erosion;

2. Control stormwater discharges, including both peak flow rates and total stormwater volume, to minimize erosion at outlets and to minimize downstream channel and stream bank erosion;

3. Minimize the amount of soil exposed during construction activity;

4. Minimize the disturbance of steep slopes;

5. Minimize sediment discharges from the site. The design, installation, and maintenance of erosion and sediment controls must address factors such as the amount, frequency, intensity, and duration of precipitation, the nature of resulting stormwater runoff, and soil characteristics, including the range of soil particle sizes expected to be present on the site;

6. Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal, and maximize stormwater infiltration, unless infeasible;

7. Minimize soil compaction and, unless infeasible, preserve topsoil;

8. Stabilization of disturbed areas must, at a minimum, be initiated immediately whenever any clearing, grading, excavating, or other earth disturbing activities have permanently ceased on any portion of the site, or temporarily ceased on any portion of the site and will not resume for a period exceeding 14 calendar days. Stabilization must be completed within a period of time determined by the VESMP authority or the department as the VSMP authority. In arid, semi-arid, and drought-stricken areas where initiating vegetative stabilization measures immediately is infeasible, alternative stabilization measures must be employed as specified by the VESMP authority or department; and

9. Utilize outlet structures that withdraw water from the surface, unless infeasible, when discharging from basins and impoundments.

G. The SWPPP shall be amended whenever there is a change in design, construction, operation, or maintenance that has a significant effect on the discharge of pollutants to state waters and that has not been previously addressed in the SWPPP. The SWPPP must be maintained at a central location onsite. If an onsite location is unavailable, notice of the SWPPP's location must be posted near the main entrance at the construction site.

A. An erosion and sediment control plan shall be filed for a development and the buildings constructed within, regardless of the phasing of construction. The erosion and sediment control plan shall contain all major conservation decisions to ensure that the entire unit of land will be so treated to achieve the conservation objectives and minimum standards in 9VAC25-875-560. The erosion and sediment control plan may include:

1. Appropriate maps;

2. An appropriate soil and water plan inventory and management information with needed interpretations; and

3. A record of decisions contributing to conservation treatment.

B. The person responsible for carrying out the plan shall provide the name of an individual holding a certificate who will be in charge of and responsible for carrying out the land-disturbing activity to the VESCP or VESMP authority. However, the VESCP or VESMP authority may waive the Responsible Land Disturber Certificate requirement for an agreement in lieu of a plan in accordance with § 62.1-44.15:34 or 62.1-44.15:55 of the Code of Virginia.

C. If individual lots or sections in a residential development are being developed by different property owners, all land-disturbing activities related to the building construction shall be covered by an erosion and sediment control plan or an agreement in lieu of a plan signed by the property owner.

D. Land-disturbing activity of less than 10,000 square feet on individual lots in a residential development shall not be considered exempt from the provisions of the VESMA, ESCL, or this chapter if the total land-disturbing activity in the development is equal to or greater than 10,000 square feet.

E. All erosion and sediment control structures and systems shall be maintained, inspected, and repaired as needed to ensure continued performance of their intended function. A statement describing the maintenance responsibilities of the individual responsible for carrying out the land-disturbing activity shall be included in the approved erosion and sediment control plan.

A. An erosion and sediment control plan consistent with the following criteria, techniques, and methods shall be submitted to the VESMP authority or VESCP authority for review and approval:

1. Permanent or temporary soil stabilization shall be applied to denuded areas within seven days after final grade is reached on any portion of the site. Temporary soil stabilization shall be applied within seven days to denuded areas that may not be at final grade but will remain dormant for longer than 14 days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year.

2. During construction of the project, soil stockpiles and borrow areas shall be stabilized or protected with sediment trapping measures. The applicant is responsible for the temporary protection and permanent stabilization of all soil stockpiles on site as well as borrow areas and soil intentionally transported from the project site.

3. A permanent vegetative cover shall be established on denuded areas not otherwise permanently stabilized. Permanent vegetation shall not be considered established until a ground cover is achieved that is uniform, is mature enough to survive, and will inhibit erosion.

4. Sediment basins and traps, perimeter dikes, sediment barriers, and other measures intended to trap sediment shall be constructed as a first step in any land-disturbing activity and shall be made functional before upslope land disturbance takes place.

5. Stabilization measures shall be applied to earthen structures such as dams, dikes, and diversions immediately after installation.

6. Sediment traps and sediment basins shall be designed and constructed based upon the total drainage area to be served by the trap or basin.

a. The minimum storage capacity of a sediment trap shall be 134 cubic yards per acre of drainage area and the trap shall only control drainage areas less than three acres.

b. Surface runoff from disturbed areas that is comprised of flow from drainage areas greater than or equal to three acres shall be controlled by a sediment basin. The minimum storage capacity of a sediment basin shall be 134 cubic yards per acre of drainage area. The outfall system shall, at a minimum, maintain the structural integrity of the basin during a 25-year storm of 24-hour duration. Runoff coefficients used in runoff calculations shall correspond to a bare earth condition or those conditions expected to exist while the sediment basin is utilized.

7. Cut and fill slopes shall be designed and constructed in a manner that will minimize erosion. Slopes that are found to be eroding excessively within one year of permanent stabilization shall be provided with additional slope stabilizing measures until the problem is corrected.

8. Concentrated runoff shall not flow down cut or fill slopes unless contained within an adequate temporary or permanent channel, flume, or slope drain structure.

9. Whenever water seeps from a slope face, adequate drainage or other protection shall be provided.

10. All storm sewer inlets that are made operable during construction shall be protected so that sediment-laden water cannot enter the conveyance system without first being filtered or otherwise treated to remove sediment.

11. Before newly constructed stormwater conveyance channels or pipes are made operational, adequate outlet protection and any required temporary or permanent channel lining shall be installed in both the conveyance channel and receiving channel.

12. When work in a live watercourse is performed, precautions shall be taken to minimize encroachment, control sediment transport, and stabilize the work area to the greatest extent possible during construction. Nonerodible material shall be used for the construction of causeways and cofferdams. Earthen fill may be used for these structures if armored by nonerodible cover materials.

13. When a live watercourse must be crossed by construction vehicles more than twice in any six-month period, a temporary vehicular stream crossing constructed of nonerodible material shall be provided.

14. All applicable federal, state, and local requirements pertaining to working in or crossing live watercourses shall be met.

15. The bed and banks of a watercourse shall be stabilized immediately after work in the watercourse is completed.

16. Underground utility lines shall be installed in accordance with the following standards in addition to other applicable criteria:

a. No more than 500 linear feet of trench may be opened at one time.

b. Excavated material shall be placed on the uphill side of trenches.

c. Effluent from dewatering operations shall be filtered or passed through an approved sediment trapping device, or both and discharged in a manner that does not adversely affect flowing streams or off-site property.

d. Material used for backfilling trenches shall be properly compacted in order to minimize erosion and promote stabilization.

e. Restabilization shall be accomplished in accordance with this chapter.

f. Applicable safety requirements shall be complied with.

17. Where construction vehicle access routes intersect paved or public roads, provisions shall be made to minimize the transport of sediment by vehicular tracking onto the paved surface. Where sediment is transported onto a paved or public road surface, the road surface shall be cleaned thoroughly at the end of each day. Sediment shall be removed from the roads by shoveling or sweeping and transported to a sediment control disposal area. Street washing shall be allowed only after sediment is removed in this manner. This provision shall apply to individual development lots as well as to larger land-disturbing activities.

18. All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after the temporary measures are no longer needed, unless otherwise authorized by the VESCP or VESMP authority. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation.

19. Properties and waterways downstream from development sites shall be protected from sediment deposition, erosion, and damage due to increases in volume, velocity, and peak flow rate of stormwater runoff for the stated frequency storm of 24-hour duration in accordance with the following standards and criteria. Stream restoration and relocation projects that incorporate natural channel design concepts are not manmade channels and shall be exempt from any flow rate capacity and velocity requirements for natural or manmade channels:

a. Concentrated stormwater runoff leaving a development site shall be discharged directly into an adequate natural or manmade receiving channel, pipe, or storm sewer system. For those sites where runoff is discharged into a pipe or pipe system, downstream stability analyses at the outfall of the pipe or pipe system shall be performed.

b. Adequacy of all channels and pipes shall be verified in the following manner:

(1) The applicant shall demonstrate that the total drainage area to the point of analysis within the channel is 100 times greater than the contributing drainage area of the project in question; or

(2) (a) Natural channels shall be analyzed by the use of a two-year storm to verify that stormwater will not overtop channel banks nor cause erosion of channel bed or banks.

(b) All previously constructed manmade channels shall be analyzed by the use of a 10-year storm to verify that stormwater will not overtop the stormwater's banks and by the use of a two-year storm to demonstrate that stormwater will not cause erosion of channel bed or banks; and

(c) Pipes and storm sewer systems shall be analyzed by the use of a 10-year storm to verify that stormwater will be contained within the pipe or system.

c. If existing natural receiving channels or previously constructed manmade channels or pipes are not adequate, the applicant shall:

(1) Improve the channels to a condition where a 10-year storm will not overtop the banks and a two-year storm will not cause erosion to the channel, the bed, or the banks;

(2) Improve the pipe or pipe system to a condition where the 10-year storm is contained within the appurtenances;

(3) Develop a site design that will not cause the predevelopment peak runoff rate from a two-year storm to increase when runoff outfalls into a natural channel or will not cause the predevelopment peak runoff rate from a 10-year storm to increase when runoff outfalls into a manmade channel; or

(4) Provide a combination of channel improvement, stormwater detention, or other measures that is satisfactory to the VESCP or VESMP authority to prevent downstream erosion.

d. The applicant shall provide evidence of permission to make the improvements.

e. All hydrologic analyses shall be based on the existing watershed characteristics and the ultimate development condition of the subject project.

f. If the applicant chooses an option that includes stormwater detention, the applicant shall obtain approval from the VESCP or VESMP authority for a plan for maintenance of the detention facilities. The plan shall set forth the maintenance requirements of the facility and the person responsible for performing the maintenance.

g. Outfall from a detention facility shall be discharged to a receiving channel, and energy dissipators shall be placed at the outfall of all detention facilities as necessary to provide a stabilized transition from the facility to the receiving channel.

h. All on-site channels must be verified to be adequate.

i. Increased volumes of sheet flows that may cause erosion or sedimentation on adjacent property shall be diverted to a stable outlet, adequate channel, pipe, or pipe system or to a detention facility.

j. In applying these stormwater management criteria, individual lots or parcels in a residential, commercial, or industrial development shall not be considered to be separate development projects. Instead, the development, as a whole, shall be considered to be a single development project. Hydrologic parameters that reflect the ultimate development condition shall be used in all engineering calculations.

k. All measures used to protect properties and waterways shall be employed in a manner that minimizes impacts on the physical, chemical, and biological integrity of rivers, streams, and other waters of the state.

l. Any plan approved prior to July 1, 2014, that provides for stormwater management that addresses any flow rate capacity and velocity requirements for natural or manmade channels shall satisfy the flow rate capacity and velocity requirements for natural or manmade channels if the practices are designed to (i) detain the water quality volume and to release it over 48 hours; (ii) detain and release over a 24-hour period the expected rainfall resulting from the one year, 24-hour storm; and (iii) reduce the allowable peak flow rate resulting from the 1.5-year, two-year, and 10-year 24-hour storms to a level that is less than or equal to the peak flow rate from the site assuming the site was in a good forested condition, achieved through multiplication of the forested peak flow rate by a reduction factor that is equal to the runoff volume from the site when the site was in a good forested condition divided by the runoff volume from the site in the site's proposed condition, and shall be exempt from any flow rate capacity and velocity requirements for natural or manmade channels as defined in any regulations promulgated pursuant to § 62.1-44.15:28 of the Code of Virginia (VESMA) or § 62.1-44.15:54 or 62.1-44.15:65 of the Code of Virginia (ESCL).

m. For plans approved on and after July 1, 2014, the flow rate capacity and velocity requirements of § 62.1-44.15:52 A of the Code of Virginia (ESCL) and this subdivision 19 shall be satisfied by compliance with water quantity requirements in the VESMA and attendant regulations, unless such land-disturbing activities (i) are in accordance with provisions for time limits on applicability of approved design criteria in 9VAC25-875-480 or grandfathering in 9VAC25-875-490, in which case the flow rate capacity and velocity requirements of § 62.1-44.15:52 A of the Code of Virginia (ESCL) shall apply; or (ii) are exempt pursuant to § 62.1-44.15:34 G 2 of the Code of Virginia (VESMA).

n. Compliance with the water quantity minimum standards set out in 9VAC25-875-600 shall be deemed to satisfy the requirements of this subdivision 19.

B. All land-disturbing activities shall be conducted in a manner that is consistent with the applicable requirements of subsection A of this section.

For the purposes of this part only, the following words and terms have the following meanings unless the context clearly indicates otherwise:

"Administrator" means the Administrator of the U.S. Environmental Protection Agency or an authorized representative.

"Applicable standards and limitations" means all state, interstate, and federal standards and limitations to which a discharge or a related activity is subject under the Clean Water Act (CWA) (33 USC § 1251 et seq.) and VESMA, including effluent limitations, water quality standards, standards of performance, toxic effluent standards or prohibitions, best management practices, and standards for sewage sludge use or disposal under §§ 301, 302, 303, 304, 306, 307, 308, 403, and 405 of the CWA.

"Approved program" or "approved state" means a state or interstate program that has been approved or authorized by EPA under 40 CFR Part 123.

"Bypass" means the intentional diversion of waste streams from any portion of a treatment facility.

"Contiguous zone" means the entire zone established by the United States under Article 24 of the Convention on the Territorial Sea and the Contiguous Zone (37 FR 11906 June 15, 1972).

"Continuous discharge" means a discharge that occurs without interruption throughout the operating hours of the facility, except for infrequent shutdowns for maintenance, process changes, or other similar activities.

"Co-permittee" means a permittee to a VPDES permit that is only responsible for permit conditions relating to the discharge for which it is the operator.

"Daily discharge" means the discharge of a pollutant measured during a calendar day or any 24-hour period that reasonably represents the calendar day for purposes of sampling. For pollutants with limitations expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For pollutants with limitations expressed in other units of measurement, the daily discharge is calculated as the average measurement of the pollutant over the day.

"Discharge" when used without qualification, means the discharge of a pollutant.

"Discharge of a pollutant" means:

1. Any addition of any pollutant or combination of pollutants to state waters from any point source; or

2. Any addition of any pollutant or combination of pollutants to the waters of the contiguous zone or the ocean from any point source other than a vessel or other floating craft that is being used as a means of transportation.

This definition includes additions of pollutants into surface waters from surface runoff that is collected or channeled by man; discharges through pipes, sewers, or other conveyances owned by a state, municipality, or other person that do not lead to a treatment works; and discharges through pipes, sewers, or other conveyances, leading into privately owned treatment works. This term does not include an addition of pollutants by any indirect discharger.

"Discharge Monitoring Report" or "DMR" means the form supplied by the department, or an equivalent form developed by the operator and approved by the department, for the reporting of self-monitoring results by operators.

"Draft permit" means a document indicating the department's tentative decision to issue or deny, modify, revoke and reissue, terminate, or reissue an individual or general permit. A notice of intent to deny an individual or general permit is a type of draft permit. A denial of a request for modification, revocation and reissuance, or termination is not a draft permit.

"Effluent limitation" means any restriction imposed by the board on quantities, discharge rates, and concentrations of pollutants that are discharged from point sources into surface waters, the waters of the contiguous zone, or the ocean.

"Effluent limitations guidelines" means a regulation published by the administrator under § 304(b) of the CWA to adopt or revise effluent limitations.

"Existing permit" means for the purposes of this chapter a permit issued by the department and currently held by a permit applicant.

"Existing source" means any source that is not a new source or a new discharger.

"Facilities or equipment" means buildings, structures, process or production equipment, or machinery that form a permanent part of a new source and that will be used in its operation if these facilities or equipment are of such value as to represent a substantial commitment to construct. The term excludes facilities or equipment used in connection with feasibility, engineering, and design studies regarding the new source or water pollution treatment for the new source.

"Facility or activity" means any VPDES point source or treatment works treating domestic sewage or any other facility or activity, including land or appurtenances thereto, that is subject to regulation under the VPDES program.

"Hazardous substance" means any substance designated under the Code of Virginia or 40 CFR Part 116 pursuant to § 311 of the CWA.

"Illicit discharge" means any discharge to a municipal separate storm sewer that is not composed entirely of stormwater, except discharges pursuant to a separate VPDES or permit (other than the permit for discharges from the municipal separate storm sewer), discharges resulting from firefighting activities, and discharges identified by and in compliance with 9VAC25-875-970 D 2 c (3).

"Indian country" means (i) all land within the limits of any Indian reservation under the jurisdiction of the United States government, notwithstanding the issuance of any patent, and including rights-of-way running through the reservation; (ii) all dependent Indian communities within the borders of the United States whether within the originally or subsequently acquired territory thereof, and whether within or without the limits of a state; and (iii) all Indian allotments, the Indian titles to which have not been extinguished, including rights-of-way running through the same.

"Indirect discharger" means a nondomestic discharger introducing "pollutants" to a "publicly owned treatment works (POTW)."

"Large municipal separate storm sewer system" means all municipal separate storm sewers that are either:

1. Located in an incorporated place with a population of 250,000 or more as determined by the 1990 decennial census by the Bureau of Census (40 CFR Part 122 Appendix F);

2. Located in the counties listed in 40 CFR Part 122 Appendix H, except municipal separate storm sewers that are located in the incorporated places, townships, or towns within such counties;

3. Owned or operated by a municipality other than those described in subdivision 1 or 2 of this definition and that are designated by the department as part of the large or medium municipal separate storm sewer system due to the interrelationship between the discharges of the designated storm sewer and the discharges from municipal separate storm sewers described under subdivision 1 or 2 of this definition. In making this determination the department may consider the following factors:

a. Physical interconnections between the municipal separate storm sewers;

b. The location of discharges from the designated municipal separate storm sewer relative to discharges from municipal separate storm sewers described in subdivision 1 of this definition;

c. The quantity and nature of pollutants discharged to surface waters;

d. The nature of the receiving surface waters; and

e. Other relevant factors;

4. The department may, upon petition, designate as a large municipal separate storm sewer system, municipal separate storm sewers located within the boundaries of a region defined by a stormwater management regional authority based on a jurisdictional, watershed, or other appropriate basis that includes one or more of the systems described in this definition.

"Major facility" means any facility or activity classified as such by the regional administrator in conjunction with the board.

"Major municipal separate storm sewer outfall" or "major outfall" means a municipal separate storm sewer outfall that discharges from a single pipe with an inside diameter of 36 inches or more or its equivalent (discharge from a single conveyance other than circular pipe which is associated with a drainage area of more than 50 acres); or for municipal separate storm sewers that receive stormwater from lands zoned for industrial activity (based on comprehensive zoning plans or the equivalent), with an outfall that discharges from a single pipe with an inside diameter of 12 inches or more or from its equivalent (discharge from other than a circular pipe associated with a drainage area of two acres or more).

"Maximum daily discharge limitation" means the highest allowable daily discharge.

"Maximum extent practicable" or "MEP" means, in the context of a municipal separate stormwater sewer system, the technology-based discharge standard for municipal separate storm sewer systems established by CWA § 402(p). MEP is achieved, in part, by selecting and implementing effective structural and nonstructural best management practices (BMPs) and rejecting ineffective BMPs and replacing them with effective best management practices (BMPs). MEP is an iterative standard, which evolves over time as urban runoff management knowledge increases. As such, the operator's MS4 program must continually be assessed and modified to incorporate improved programs, control measures, and BMPs to attain compliance with water quality standards.

"Medium municipal separate storm sewer system" means all municipal separate storm sewers that are either:

1. Located in an incorporated place with a population of 100,000 or more but less than 250,000 as determined by the 1990 decennial census by the Bureau of Census (40 CFR Part 122 Appendix G);

2. Located in the counties listed in 40 CFR Part 122 Appendix I, except municipal separate storm sewers that are located in the incorporated places, townships, or towns within such counties;

3. Owned or operated by a municipality other than those described in subdivision 1 or 2 of this definition and that are designated by the department as part of the large or medium municipal separate storm sewer system due to the interrelationship between the discharges of the designated storm sewer and the discharges from municipal separate storm sewers described under subdivision 1 or 2 of this definition. In making this determination the department may consider the following factors:

a. Physical interconnections between the municipal separate storm sewers;

b. The location of discharges from the designated municipal separate storm sewer relative to discharges from municipal separate storm sewers described in subdivision 1 of this definition;

c. The quantity and nature of pollutants discharged to surface waters;

d. The nature of the receiving surface waters; or

e. Other relevant factors;

4. The department may, upon petition, designate as a medium municipal separate storm sewer system, municipal separate storm sewers located within the boundaries of a region defined by a stormwater management regional authority based on a jurisdictional, watershed, or other appropriate basis that includes one or more of the systems described in subdivisions 1, 2, and 3 of this definition.

"Municipality" means a city, town, county, district, association, or other public body created by or under state law and having jurisdiction over disposal of sewage, industrial wastes, or other wastes or an Indian tribe or an authorized Indian tribal organization or a designated and approved management agency under § 208 of the CWA.

"New discharger" means any building, structure, facility, or installation:

1. From which there is or may be a discharge of pollutants;

2. That did not commence the discharge of pollutants at a particular site prior to August 13, 1979;

3. Which is not a new source; and

4. Which has never received a finally effective separate VPDES or permit for discharges at that site.

This definition includes an indirect discharger that commences discharging into surface waters after August 13, 1979. It also includes any existing mobile point source (other than an offshore or coastal oil and gas exploratory drilling rig or a coastal oil and gas developmental drilling rig) such as a seafood processing rig, seafood processing vessel, or aggregate plant that begins discharging at a site for which it does not have a separate VPDES or permit, and any offshore or coastal mobile oil and gas exploratory drilling rig or coastal mobile oil and gas developmental drilling rig that commences the discharge of pollutants after August 13, 1979.

"New source" means any building, structure, facility, or installation from which there is or may be a discharge of pollutants, the construction of which commenced:

1. After promulgation of standards of performance under § 306 of the CWA that are applicable to such source; or

2. After proposal of standards of performance in accordance with § 306 of the CWA that are applicable to such source, but only if the standards are promulgated in accordance with § 306 of the CWA within 120 days of their proposal.

"Oil and gas exploration, production, processing, or treatment operations or transmission facilities" means all field activities or operations associated with exploration, production, or treatment operations, or transmission facilities, including activities necessary to prepare a site for drilling and for the movement and placement of drilling equipment, whether or not such field activities or operations may be considered to be construction activity. (33 USC § 1362(24))

"Outfall," when used in reference to municipal separate storm sewers, means a point source at the point where a municipal separate storm sewer discharges to surface waters and does not include open conveyances connecting two municipal separate storm sewers, or pipes, tunnels, or other conveyances that connect segments of the same stream or other surface waters and are used to convey surface waters.

"Overburden" means any material of any nature, consolidated or unconsolidated, that overlies a mineral deposit, excluding topsoil or similar naturally occurring surface materials that are not disturbed by mining operations.

"Permit" means a VPDES permit issued by the department pursuant to § 62.1-44.15 of the Code of Virginia for stormwater discharges from a land-disturbing activity or MS4.

"Pollutant" means dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials (except those regulated under the Atomic Energy Act of 1954, as amended (42 USC § 2011 et seq.)), heat, wrecked or discarded equipment, rock, sand, cellar dirt and industrial, municipal, and agricultural waste discharged into water. It does not mean:

1. Sewage from vessels; or

2. Water, gas, or other material that is injected into a well to facilitate production of oil or gas or water derived in association with oil and gas production and disposed of in a well if the well is used either to facilitate production or for disposal purposes is approved by the department and if the department determines that the injection or disposal will not result in the degradation of groundwater or surface water resources.

"Privately owned treatment works" or "PVOTW" means any device or system that is (i) used to treat wastes from any facility whose operator is not the operator of the treatment works and (ii) not a POTW.

"Publicly owned treatment works" or "POTW" means a treatment works as defined by § 212 of the CWA that is owned by a state or municipality (as defined by § 502(4) of the CWA). This definition includes any devices and systems used in the storage, treatment, recycling, and reclamation of municipal sewage or industrial wastes of a liquid nature. It also includes sewers, pipes, and other conveyances only if they convey wastewater to a POTW treatment plant. The term also means the municipality as defined in § 502(4) of the CWA, that has jurisdiction over the indirect discharges to and the discharges from such a treatment works.

"Recommencing discharger" means a source that recommences discharge after terminating operations.

"Regional administrator" means the Regional Administrator of Region III of the Environmental Protection Agency or the authorized representative of the regional administrator.

"Revoked" means an existing VPDES permit that is terminated by the department before its expiration.

"Runoff coefficient" means the fraction of total rainfall that will appear at a conveyance as runoff.

"Schedule of compliance" means a schedule of remedial measures included in a permit, including an enforceable sequence of interim requirements (for example, actions, operations, or milestone events) leading to compliance with the VESMA, the CWA, and regulations.

"Secretary" means the Secretary of the Army, acting through the Chief of Engineers.

"Severe property damage" means substantial physical damage to property, damage to the treatment facilities that causes them to become inoperable, or substantial and permanent loss of natural resources that can reasonably be expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in production.

"Significant materials" means but is not limited to raw materials; fuels; materials such as solvents, detergents, and plastic pellets; finished materials such as metallic products; raw materials used in food processing or production; hazardous substances designated under § 101(14) of CERCLA (42 USC § 9601(14)); any chemical the facility is required to report pursuant to § 313 of Title III of SARA (42 USC § 11023); fertilizers; pesticides; and waste products such as ashes, slag, and sludge that have the potential to be released with stormwater discharges.

"Small municipal separate storm sewer system" or "small MS4" means all separate storm sewers that are (i) owned or operated by the United States, a state, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to state law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under state law such as a sewer district, flood control district or drainage district, or similar entity or an Indian tribe or an authorized Indian tribal organization or a designated and approved management agency under § 208 of the CWA that discharges to surface waters and (ii) not defined as "large" or "medium" municipal separate storm sewer systems or designated under 9VAC25-875-950 A 1. This term includes systems similar to separate storm sewer systems in municipalities, such as systems at military bases, large hospital or prison complexes, and highway and other thoroughfares. The term does not include separate storm sewers in very discrete areas, such as individual buildings.

"Source" means any building, structure, facility, or installation from which there is or may be a discharge of pollutants.

"Stormwater discharge associated with construction activity" means a discharge of stormwater runoff from areas where land-disturbing activities (e.g., clearing, grading, or excavation); construction materials or equipment storage or maintenance (e.g., fill piles, borrow area, concrete truck washout, fueling); or other industrial stormwater directly related to the construction process (e.g., concrete or asphalt batch plants) are located.

"Stormwater discharge associated with large construction activity" means the discharge of stormwater from large construction activities.

"Stormwater discharge associated with small construction activity" means the discharge of stormwater from small construction activities.

"Total dissolved solids" means the total dissolved (filterable) solids as determined by use of the method specified in 40 CFR Part 136.

"Toxic pollutant" means any pollutant listed as toxic under § 307(a)(1) of the CWA or, in the case of sludge use or disposal practices, any pollutant identified in regulations implementing § 405(d) of the CWA.

"Upset" means an exceptional incident in which there is unintentional and temporary noncompliance with technology based permit effluent limitations because of factors beyond the reasonable control of the operator. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation.

"Variance" means any mechanism or provision under § 301 or 316 of the CWA or under 40 CFR Part 125, or in the applicable federal effluent limitations guidelines that allows modification to or waiver of the generally applicable effluent limitation requirements or time deadlines of the CWA. This includes provisions that allow the establishment of alternative limitations based on fundamentally different factors or on § 301(c), (g), (h), or (i), or 316(a) of the CWA.

"Virginia Pollutant Discharge Elimination System permit" or "VPDES permit" means a document issued by the department pursuant to the State Water Control Law authorizing, under prescribed conditions, the potential or actual discharge of pollutants from a point source to surface waters.

"Water quality standards" or "WQS" means provisions of state or federal law that consist of a designated use or uses for the waters of the Commonwealth and water quality criteria for such waters based on such uses. Water quality standards are to protect the public health or welfare, enhance the quality of water, and serve the purposes of the State Water Control Law (§ 62.1-44.2 et seq. of the Code of Virginia), the VESMA (§ 62.1-44.15:24 et seq. of the Code of Virginia), and the CWA (33 USC § 1251 et seq.).

"Whole effluent toxicity" means the aggregate toxic effect of an effluent measured directly by a toxicity test.