Through their applicable land use ordinances, regulations, and enforcement mechanisms, local governments shall require that any use, development, or redevelopment of land in Chesapeake Bay Preservation Areas meets the following performance criteria:

1. No more land shall be disturbed than is necessary to provide for the proposed use or development.

2. Indigenous vegetation shall be preserved to the maximum extent practicable, consistent with the use or development proposed. Mature trees shall only be removed where determined to be necessary to provide for the proposed use or development and protected during development to the maximum extent practicable.

3. All development exceeding 2,500 square feet of land disturbance shall be accomplished through a plan of development review process consistent with § 15.2-2286 A 8 of the Code of Virginia and subdivision 1 e of 9VAC25-830-240.

4. Land development shall minimize impervious cover consistent with the proposed use or development.

5. Any land disturbing activity that exceeds an area of 2,500 square feet (including construction of all single family houses, septic tanks, and drainfields, but otherwise as defined in § 62.1-44.15:51 of the Code of Virginia) shall comply with the requirements of the local erosion and sediment control ordinance. Enforcement for noncompliance with the erosion and sediment control requirements referenced in this criterion shall be conducted under the provisions of the Erosion and Sediment Control Law and attendant regulations.

6. Any Chesapeake Bay Preservation Act land-disturbing activity as defined in § 62.1-44.15:24 of the Code of Virginia shall comply with the requirements of 9VAC25-870-51 and 9VAC25-870-103.

7. Onsite sewage treatment systems not requiring a Virginia Pollutant Discharge Elimination System (VPDES) permit shall:

a. Have pump-out accomplished for all such systems at least once every five years.

(1) If deemed appropriate by the local health department and subject to conditions the local health department may set, local governments may offer to the owners of such systems, as an alternative to the mandatory pump-out, the option of having a plastic filter installed and maintained in the outflow pipe from the septic tank to filter solid material from the effluent while sustaining adequate flow to the drainfield to permit normal use of the septic system. Such a filter should satisfy standards established in the Sewage Handling and Disposal Regulations (12VAC5-610) administered by the Virginia Department of Health.

(2) Furthermore, in lieu of requiring proof of septic tank pump-out every five years, local governments may allow owners of onsite sewage treatment systems to submit documentation every five years, certified by an operator or onsite soil evaluator licensed or certified under Chapter 23 (§ 54.1-2300 et seq.) of Title 54.1 of the Code of Virginia as being qualified to operate, maintain, or design onsite sewage systems, that the septic system has been inspected, is functioning properly, and the tank does not need to have the effluent pumped out of it.

b. For new construction, provide a reserve sewage disposal site with a capacity at least equal to that of the primary sewage disposal site. This reserve sewage disposal site requirement shall not apply to any lot or parcel recorded prior to October 1, 1989, if the lot or parcel is not sufficient in capacity to accommodate a reserve sewage disposal site, as determined by the local health department. Building shall be prohibited on the area of all sewage disposal sites until the structure is served by public sewer or an onsite sewage treatment system that operates under a permit issued by the board. All sewage disposal site records shall be administered to provide adequate notice and enforcement. As an alternative to the 100% reserve sewage disposal site, local governments may offer the owners of such systems the option of installing an alternating drainfield system meeting the following conditions:

(1) Each of the two alternating drainfields in the system shall have, at a minimum, an area not less than 50% of the area that would otherwise be required if a single primary drainfield were constructed.

(2) An area equaling 50% of the area that would otherwise be required for the primary drainfield site must be reserved for subsurface absorption systems that utilize a flow diversion device, in order to provide for future replacement or repair to meet the requirements for a sewage disposal system. Expansion of the primary system will require an expansion of this reserve area.

(3) The two alternating drainfields shall be connected by a diversion valve, approved by the local health department, located in the pipe between the septic (aerobic) tank and the distribution boxes. The diversion valve shall be used to alternate the direction of effluent flow to one drainfield or the other at a time. However, diversion valves shall not be used for the following types of treatment systems:

(a) Sand mounds;

(b) Low-pressure distribution systems;

(c) Repair situations when installation of a valve is not feasible; and

(d) Any other approved system for which the use of a valve would adversely affect the design of the system, as determined by the local health department.

(4) The diversion valve shall be a three-port, two-way valve of approved materials (i.e., resistant to sewage and leakproof and designed so that the effluent from the tank can be directed to flow into either one of the two distribution boxes).

(5) There shall be a conduit from the top of the valve to the ground surface with an appropriate cover to be level with or above the ground surface.

(6) The valve shall not be located in driveways, recreational courts, parking lots, or beneath sheds or other structures.

(7) In lieu of the aforementioned diversion valve, any device that can be designed and constructed to conveniently direct the flow of effluent from the tank into either one of the two distribution boxes may be approved if plans are submitted to the local health department and found to be satisfactory.

(8) The local government shall require that the owner(s) owner alternate the drainfields every 12 months to permit the yearly resting of half of the absorption system.

(9) The local government shall ensure that the owner(s) owner are notified annually of the requirement to switch the valve to the opposite drainfield.

8. Land upon which agricultural activities are being conducted, including but not limited to crop production, pasture, and dairy and feedlot operations, or lands otherwise defined as agricultural land by the local government, shall have a soil and water quality conservation assessment conducted that evaluates the effectiveness of existing practices pertaining to soil erosion and sediment control, nutrient management, and management of pesticides, and, where necessary, results in a plan that outlines additional practices needed to ensure that water quality protection is being accomplished consistent with the Act and this chapter.

a. Recommendations for additional conservation practices need address only those conservation issues applicable to the tract or field being assessed. Any soil and water quality conservation practices that are recommended as a result of such an assessment and are subsequently implemented with financial assistance from federal or state cost-share programs must be designed, consistent with cost-share practice standards effective in January 1999 in the "Field Office Technical Guide" of the U.S. Department of Agriculture Natural Resource Conservation Service or the June 2000 edition of the "Virginia Agricultural BMP Manual" of the Virginia Department of Conservation and Recreation, respectively. Unless otherwise specified in this section, general standards pertaining to the various agricultural conservation practices being assessed shall be as follows:

(1) For erosion and sediment control recommendations, the goal shall be, where feasible, to prevent erosion from exceeding the soil loss tolerance level, referred to as "T," as defined in the "National Soil Survey Handbook" of November 1996 in the "Field Office Technical Guide" of the U.S. Department of Agriculture Natural Resource Conservation Service. However, in no case shall erosion exceed the soil loss consistent with an Alternative Conservation System, referred to as an "ACS", as defined in the "Field Office Technical Guide" of the U.S. Department of Agriculture Natural Resource Conservation Service.

(2) For nutrient management, whenever nutrient management plans are developed, the operator or landowner must provide soil test information, consistent with the Virginia Nutrient Management Training and Certification Regulations (4VAC50-85).

(3) For pest chemical control, referrals shall be made to the local cooperative extension agent or an Integrated Pest Management Specialist of the Virginia Cooperative Extension Service. Recommendations shall include copies of applicable information from the "Virginia Pest Management Guide" or other Extension materials related to pest control.

b. A higher priority shall be placed on conducting assessments of agricultural fields and tracts adjacent to Resource Protection Areas. However, if the landowner or operator of such a tract also has Resource Management Area fields or tracts in his operation, the assessment for that landowner or operator may be conducted for all fields or tracts in the operation. When such an expanded assessment is completed, priority must return to Resource Protection Area fields and tracts.

c. The findings and recommendations of such assessments and any resulting soil and water quality conservation plans will be submitted to the local Soil and Water Conservation District Board, which will be the plan-approving authority.

9. Silvicultural activities in Chesapeake Bay Preservation Areas are exempt from this chapter provided that silvicultural operations adhere to water quality protection procedures prescribed by the Virginia Department of Forestry in the Fifth Edition (March 2011) of "Virginia's Forestry Best Management Practices for Water Quality Technical Manual." The Virginia Department of Forestry will oversee and document installation of best management practices and will monitor in-stream impacts of forestry operations in Chesapeake Bay Preservation Areas.

10. Local governments shall require evidence of all wetlands permits required by law prior to authorizing grading or other onsite activities to begin.

In addition to the general performance criteria set forth in 9VAC25-830-130, the criteria in this section are applicable in Resource Protection Areas.

1. Land development may be allowed in the Resource Protection Area, subject to approval by the local government, only if it (i) is water dependent; (ii) constitutes redevelopment; (iii) constitutes development or redevelopment within a designated Intensely Developed Area; (iv) is a new use established pursuant to subdivision 4 a of this section; (v) is a road or driveway crossing satisfying the conditions set forth in subdivision 1 d of this section; or (vi) is a flood control or stormwater management facility satisfying the conditions set forth in subdivision 1 e of this section.

a. A water quality impact assessment in accordance with subdivision 6 of this section shall be required for any proposed land disturbance.

b. A new or expanded water-dependent facility may be allowed provided that the following criteria are met:

(1) It does not conflict with the comprehensive plan;

(2) It complies with the performance criteria set forth in 9VAC25-830-130;

(3) Any nonwater-dependent component is located outside of Resource Protection Areas; and

(4) Access to the water-dependent facility will be provided with the minimum disturbance necessary. Where practicable, a single point of access will be provided.

c. Redevelopment outside locally designated Intensely Developed Areas shall be permitted in the Resource Protection Area only if there is no increase in the amount of imperious cover and no further encroachment within the Resource Protection Area, and it shall conform to applicable erosion and sediment control and stormwater management criteria set forth in the Erosion and Sediment Control Law and the Virginia Stormwater Management Act and their attendant regulations, as well as all applicable stormwater management requirements of other state and federal agencies.

d. Roads and driveways not exempt under subdivision B 1 of 9VAC25-830-150 and which, therefore, must comply with the provisions of this chapter, may be constructed in or across Resource Protection Areas if each of the following conditions is met:

(1) The local government makes a finding that there are no reasonable alternatives to aligning the road or driveway in or across the Resource Protection Area;

(2) The alignment and design of the road or driveway are optimized, consistent with other applicable requirements, to minimize (i) encroachment in the Resource Protection Area and (ii) adverse effects on water quality;

(3) The design and construction of the road or driveway satisfy all applicable criteria of this chapter, including submission of a water quality impact assessment; and

(4) The local government reviews the plan for the road or driveway proposed in or across the Resource Protection Area in coordination with local government site plan, subdivision and plan of development approvals.

e. Flood control and stormwater management facilities that drain or treat water from multiple development projects or from a significant portion of a watershed may be allowed in Resource Protection Areas provided such facilities are allowed and constructed in accordance with the Virginia Stormwater Management Act and its attendant regulations, and provided that (i) the local government has conclusively established that location of the facility within the Resource Protection Area is the optimum location; (ii) the size of the facility is the minimum necessary to provide necessary flood control or stormwater treatment, or both; (iii) the facility must be consistent with a comprehensive stormwater management plan developed and approved in accordance with 9VAC25-870-92 of the Virginia Stormwater Management Program (VSMP) regulations; (iv) all applicable permits for construction in state or federal waters must be obtained from the appropriate state and federal agencies, such as the U.S. Army Corps of Engineers, the department, and the Virginia Marine Resources Commission; (v) approval must be received from the local government prior to construction; and (vi) routine maintenance is allowed to be performed on such facilities to assure that they continue to function as designed. It is not the intent of this subdivision to allow a best management practice that collects and treats runoff from only an individual lot or some portion of the lot to be located within a Resource Protection Area.

2. Exemptions in Resource Protection Areas. The following land disturbances in Resource Protection Areas may be exempt from the criteria of this part provided that they comply with subdivisions a and b of this subdivision 2: (i) water wells; (ii) passive recreation facilities such as boardwalks, trails, and pathways; and (iii) historic preservation and archaeological activities:

a. Local governments shall establish administrative procedures to review such exemptions.

b. Any land disturbance exceeding an area of 2,500 square feet shall comply with the erosion and sediment control criteria in subdivision 5 of 9VAC25-830-130.

3. Buffer area requirements. The 100-foot wide buffer area shall be the landward component of the Resource Protection Area as set forth in subdivision B 5 of 9VAC25-830-80. Notwithstanding permitted uses, encroachments, and vegetation clearing, as set forth in this section, the 100-foot wide buffer area is not reduced in width. To minimize the adverse effects of human activities on the other components of the Resource Protection Area, state waters, and aquatic life, a 100-foot wide buffer area of vegetation that is effective in retarding runoff, preventing erosion, and filtering nonpoint source pollution from runoff shall be retained if present and established where it does not exist. Where such buffer must be established, the planting of trees should be utilized to the maximum extent practicable and appropriate to site conditions.

a. The 100-foot wide buffer area shall be deemed to achieve a 75% reduction of sediments and a 40% reduction of nutrients.

b. Where land uses such as agriculture or silviculture within the area of the buffer cease and the lands are proposed to be converted to other uses, the full 100-foot wide buffer shall be reestablished. In reestablishing the buffer, management measures shall be undertaken to provide woody vegetation that assures the buffer functions set forth in this chapter. Such measures should include to the maximum extent practicable and appropriate to site conditions the planting of trees in reestablishing the buffer.

4. Permitted encroachments into the buffer area.

a. When the application of the buffer area would result in the loss of a buildable area on a lot or parcel recorded prior to October 1, 1989, encroachments into the buffer area may be allowed through an administrative process in accordance with the following criteria:

(1) Encroachments into the buffer area shall be the minimum necessary to achieve a reasonable buildable area for a principal structure and necessary utilities.

(2) Where practicable, a vegetated area that will maximize water quality protection, mitigate the effects of the buffer encroachment, and is equal to the area of encroachment into the buffer area shall be established elsewhere on the lot or parcel. Such vegetated area where established should include the planting of trees to the maximum extent practicable.

(3) The encroachment may not extend into the seaward 50 feet of the buffer area.

b. When the application of the buffer area would result in the loss of a buildable area on a lot or parcel recorded between October 1, 1989, and March 1, 2002, encroachments into the buffer area may be allowed through an administrative process in accordance with the following criteria:

(1) The lot or parcel was created as a result of a legal process conducted in conformity with the local government's subdivision regulations;

(2) Conditions or mitigation measures imposed through a previously approved exception shall be met;

(3) If the use of a best management practice (BMP) was previously required, the BMP shall be evaluated to determine if it continues to function effectively and, if necessary, the BMP shall be reestablished or repaired and maintained as required; and

(4) The criteria in subdivision 4 a of this section shall be met.

5. Permitted modifications of the buffer area.

a. In order to maintain the functional value of the buffer area, existing vegetation may be removed, subject to approval by the local government, only to provide for reasonable sight lines, access paths, general woodlot management, and best management practices, including those that prevent upland erosion and concentrated flows of stormwater, as follows:

(1) Trees may be pruned or removed as necessary to provide for sight lines and vistas, provided that where removed, they shall be replaced with other vegetation that is equally effective in retarding runoff, preventing erosion, and filtering nonpoint source pollution from runoff. Mature trees should be preserved and not removed to the maximum extent practicable under this provision. When trees are removed, the other vegetation to replace the trees should be trees as well to the maximum extent practicable.

(2) Any path shall be constructed and surfaced so as to effectively control erosion.

(3) Dead, diseased, or dying trees or shrubbery and noxious weeds (such as Johnson grass, kudzu, and multiflora rose) may be removed and thinning of trees may be allowed pursuant to sound horticultural practice incorporated into locally-adopted standards.

(4) For shoreline erosion control projects, trees and woody vegetation may be removed, necessary control techniques employed, and appropriate vegetation established to protect or stabilize the shoreline in accordance with the best available technical advice and applicable permit conditions or requirements. Mature trees should be preserved to the maximum extent practicable consistent with the best available technical advice and permit conditions or requirements and trees should be utilized in the projects to the maximum extent practicable.

b. On agricultural lands the agricultural buffer area shall be managed to prevent concentrated flows of surface water from breaching the buffer area and appropriate measures may be taken to prevent noxious weeds (such as Johnson grass, kudzu, and multiflora rose) from invading the buffer area. Agricultural activities may encroach into the buffer area as follows:

(1) Agricultural activities may encroach into the landward 50 feet of the 100-foot wide buffer area when at least one agricultural best management practice which, in the opinion of the local soil and water conservation district board, addresses the more predominant water quality issue on the adjacent land—erosion control or nutrient management—is being implemented on the adjacent land, provided that the combination of the undisturbed buffer area and the best management practice achieves water quality protection, pollutant removal, and water resource conservation at least the equivalent of the 100-foot wide buffer area. If nutrient management is identified as the predominant water quality issue, a nutrient management plan, including soil tests, must be developed consistent with the Virginia Nutrient Management Training and Certification Regulations (4VAC5-15) (4VAC50-85) administered by the Virginia Department of Soil and Water Conservation and Recreation Board.

(2) Agricultural activities may encroach within the landward 75 feet of the 100-foot wide buffer area when agricultural best management practices which address erosion control, nutrient management, and pest chemical control, are being implemented on the adjacent land. The erosion control practices must prevent erosion from exceeding the soil loss tolerance level, referred to as "T," as defined in the "National Soil Survey Handbook" of November 1996 in the "Field Office Technical Guide" of the U.S. Department of Agriculture Natural Resource Conservation Service. A nutrient management plan, including soil tests, must be developed, consistent with the Virginia Nutrient Management Training and Certification Regulations (4VAC5-15) (4VAC50-85) administered by the Virginia Department of Soil and Water Conservation and Recreation Board. In conjunction with the remaining buffer area, this collection of best management practices shall be presumed to achieve water quality protection at least the equivalent of that provided by the 100-foot wide buffer area.

(3) The buffer area is not required to be designated adjacent to agricultural drainage ditches if at least one best management practice which, in the opinion of the local soil and water conservation district board, addresses the more predominant water quality issue on the adjacent land—either erosion control or nutrient management—is being implemented on the adjacent land.

(4) If specific problems are identified pertaining to agricultural activities that are causing pollution of the nearby water body with perennial flow or violate performance standards pertaining to the vegetated buffer area, the local government, in cooperation with soil and water conservation district, shall recommend a compliance schedule to the landowner and require the problems to be corrected consistent with that schedule. This schedule shall expedite environmental protection while taking into account the seasons and other temporal considerations so that the probability for successfully implementing the corrective measures is greatest.

(5) In cases where the landowner or his the landowner's agent or operator has refused assistance from the local soil and water conservation district in complying with or documenting compliance with the agricultural requirements of this chapter, the district shall report the noncompliance to the local government. The local government shall require the landowner to correct the problems within a specified period of time not to exceed 18 months from their initial notification of the deficiencies to the landowner. The local government, in cooperation with the district, shall recommend a compliance schedule to the landowner. This schedule shall expedite environmental protection while taking into account the seasons and other temporal considerations so that the probability for successfully implementing the corrective measures is greatest.

6. Water quality impact assessment. A water quality impact assessment shall be required for any proposed development within the Resource Protection Area consistent with this part and for any other development in Chesapeake Bay Preservation Areas that may warrant such assessment because of the unique characteristics of the site or intensity of the proposed use or development.

a. The purpose of the water quality impact assessment is to identify the impacts of proposed development on water quality and lands in the Resource Protection Areas consistent with the goals and objectives of the Act, this chapter, and local programs, and to determine specific measures for mitigation of those impacts. The specific content and procedures for the water quality impact assessment shall be established by each local government. Local governments should notify the board of all development requiring such an assessment.

b. The water quality impact assessment shall be of sufficient specificity to demonstrate compliance with the criteria of the local program.

7. Buffer area requirements for Intensely Developed Areas. In Intensely Developed Areas the local government may exercise discretion regarding whether to require establishment of vegetation in the 100-foot wide buffer area. However, while the immediate establishment of vegetation in the buffer area may be impractical, local governments shall give consideration to implementing measures that would establish vegetation in the buffer in these areas over time in order to maximize water quality protection, pollutant removal, and water resource conservation. In considering such measures, the local government should consider the planting of trees as a part of any such measures.