Title of Regulation: 12VAC5-613. Regulations for Alternative Onsite Sewage Systems (adding 12VAC5-613-10 through 12VAC5-613-200).

Statutory Authority: §§ 32.1-12, and 32.1-164 of the Code of Virginia.

Public Hearing Information: No public hearings are scheduled.

Public Comment Deadline: February 4, 2011.

Agency Contact: Allen Knapp, Director, Division of Onsite Sewage and Wastewater Services, Department of Health, 109 Governor Street, Richmond, VA 23219, telephone (804) 864-7470, or email allen.knapp@vdh.virginia.gov.

Basis: Section 32.1-12 of the Code of Virginia authorizes the Board of Health to promulgate and enforce regulations. Under § 32.1-164 of the Code of Virginia, the board is authorized to promulgate regulations governing onsite sewage systems to protect public health and is required to exercise due diligence to protect the quality of both surface water and ground water. Section 32.164 H and I of the Code of Virginia require the board to establish a program for operation and maintenance of alternative onsite sewage systems (AOSSs) and to promulgate regulations for AOSSs. Chapter 220 of the 2009 Acts of Assembly required the board to adopt emergency regulations for operation, maintenance, performance requirements, and horizontal setback requirements for AOSSs necessary to protect public health and the environment. The emergency regulations became effective on April 7, 2010. The emergency regulations remain effective for 12 months; thus, they are set to expire on April 6, 2011. This current regulatory action is intended to replace the emergency regulations.

Purpose: The new regulation is necessary in order to carry out the board's mandates regarding AOSSs with respect to (i) performance requirements; (ii) operation and maintenance requirements; and (iii) horizontal setbacks for AOSSs designed pursuant to § 32.1-163.6 of the Code of Virginia.

The needs and goals for this regulation fall into three conceptual areas:

1. The current performance requirements contained in the Sewage Handling and Disposal Regulations are inadequate for AOSSs.

2. Statutory changes in 2008 (§ 32.1-163.6) allow licensed professional engineers to design AOSSs that are not required to comply with the Sewage Handling and Disposal Regulations. Instead, these designs must be compliant with performance requirements established by the board. Since current performance requirements are inadequate, these regulations seek to establish measurable performance requirements appropriate for all AOSSs, including the engineered designs under § 32.1-163.6.

3. Proper operation and maintenance are essential to ensure that AOSSs function as designed to protect public and environmental health.

Substance: This proposed regulation contains the following provisions:

1. Definitions, the most relevant being: standard engineering practice, best management practice, general approval, pollution, renewable operating permit, state waters, treatment levels 2 and 3, relationship with an operator, Chesapeake Bay Watershed, ground water, direct dispersal of effluent to ground water, and wetlands.

2. It is deemed a violation of these regulations if any AOSS fails to (i) achieve one or more performance requirements; (ii) accomplish any mandated visit by an operator; or (iii) accomplish any operation, maintenance, monitoring, sampling, reporting, repair, or inspection requirement. Also, a violation of an operation and maintenance manual is a violation of the regulations if it results in a violation of one or more performance requirements.

3. Before the Virginia Department of Health (VDH) will issue an operation permit for an AOSS, the owner must establish a relationship with a licensed operator. The owner must maintain a relationship with an operator during any period that the AOSS is operational.

4. Before VDH will issue an operation permit for an AOSS serving a residential structure, the property owner must record an instrument that complies with § 15.2-2157 E of the Code of Virginia in the land records of the appropriate circuit court.

5. A requirement that all plans and specifications for AOSSs are either sealed by a professional engineer or contain a certification statement claiming an appropriate exemption from the practice of engineering.

6. A requirement that applications submitted under § 32.1-163.6 of the Code of Virginia include a site characterization report.

7. Establishment of the framework for an evaluation and testing protocol for generally approved treatment units to be developed by the division through a guidance document at a later date. In addition, these regulations contain a five-year sunset provision for treatment units that have been conferred general approval on or before the effective date of this chapter. After the five-year period has elapsed, these treatment units must follow the evaluation and testing protocol in effect at the time of reapplication in order to obtain general approval.

8. A number of performance requirements for AOSSs that include:

a. A prohibition against the presence of raw or partially treated sewage on the ground surface;

b. A prohibition against the backup of sewage into plumbing fixtures;

c. Maximum trench bottom hydraulic loading rates based on two different effluent qualities (TL-2, and TL-3);

d. A requirement that STE may only be discharged to a soil treatment area when the vertical separation to a limiting feature consists of at least 18 inches of naturally-occurring, in-situ soil;

e. A requirement that AOSSs designed to disperse STE have at least 12 inches of soil cover over the soil treatment area;

f. A requirement that dosing of a treatment unit shall accommodate the designs peak flow;

g. Whenever a site has ground water at less than six inches from the surface or there is less than 18 inches of vertical separation from the point of effluent application to the bottom of a trench or other excavation, then the designer must demonstrate that water mounding will not adversely affect the functioning of the soil treatment area. The designer must provide additional studies demonstrating that the site is not flooded during the wet season and that there is sufficient hydraulic gradient to move effluent off the site without ponding;

h. When standard disinfection is required, the fecal coliform effluent quality prior to dispersal to the soil treatment area must not exceed 200 cfu/100 ml;

i. The following performance requirements related to site conditions (vertical separation to limiting features) and effluent quality:

(1) Sites with less than 18 inches of vertical separation, but at least 12 inches of vertical separation and six inches of naturally occurring, undisturbed soils, require a minimum of TL-2 effluent;

(2) Sites with less than 12 inches vertical separation must apply a minimum of TL-3 effluent with disinfection. However, if the site has less than six inches of vertical separation from a perched or seasonal water table, then it must also comply with additional ground water protection standards enumerated in 12VAC5-613-90;

j. Organic loading rates cannot exceed 0.00021 BOD lb/day/sf on a trench bottom basis;

k. Large AOSSs that are not situated in the Chesapeake Bay Watershed must comply with a total nitrogen limit of five mg/l at the project area boundary. As a precondition to the issuance of an operation permit, the designer is required to provide calculations and modeling to demonstrate that the proposed AOSS will meet this nitrogen requirement;

l. AOSSs must be designed and constructed so as to be structurally sound, resist infiltration and inflow, minimize odor or other nuisances, and maintain forward flow;

m. When sand, soil, or soil-like material is used to increase the vertical separation, the designer shall specify methods and materials that will achieve the performance requirements of the regulations;

n. Septic tank effluent is prohibited for large AOSSs;

o. AOSSs with soil dispersal systems installed with less than six inches of vertical separation to ground water must meet the following requirements:

(1) If the concentration of any constituent in ground water is less than the limits set forth in 9VAC25-280, then the natural quality for the constituent must be maintained; natural quality must also be maintained for all constituents not set forth in 9VAC25-280. If the concentration of any constituent in ground water exceeds the limit set forth in the regulatory standard for that constituent, then no addition of that constituent to the naturally occurring concentration can occur;

(2) Ground water monitoring to confirm compliance with ground water quality standards must be undertaken for large AOSSs;

(3) Additional effluent monitoring is required for small AOSSs;

(4) A renewable operating permit must be obtained and maintained in accordance with the regulations;

(5) The designer must provide analyses demonstrating that the system will function as designed for the life of the structure without degrading the soil treatment area; and

(6) The systems must comply with the enumerated effluent quality standards for BOD, TSS, total nitrogen, fecal coliform, and total phosphorous. In addition, high level disinfection is required and the systems must incorporate filtration capable of demonstrating compliance with the enumerated turbidity standard;

p. AOSSs in the Chesapeake Bay Watershed must provide a 50% reduction of Total Nitrogen (TN) as compared to conventional systems which must be demonstrated either through compliance with the divisions BMPs or through sufficient calculations. In addition, large AOSSs in the Chesapeake Bay Watershed must demonstrate less than 3 mg/L TN at the project boundary and ground water monitoring for large AOSSs may be required;

q. Laboratory sampling is required for all AOSSs except those designed to disperse septic tank effluent;

r. A small AOSS using a treatment unit with general approval is required to be sampled once during the first 180 days of operation and then once every five years thereafter;

s. A small AOSS using a treatment unit that does not have general approval is required to be sampled once during the first 180 days of operation, with four additional samples to follow within the first two years of operation, and an annual sample thereafter. However, if four or more consecutive samples demonstrate compliance with applicable performance requirements, then the owner may petition VDH to have the sampling frequency reduced to once every five years;

t. Samples for small AOSSs must be analyzed for BOD₅ and, if disinfection is required, fecal coliform organisms. Small AOSSs using chlorine as a disinfectant may sample for total residual chlorine instead of fecal coliform organisms;

u. Small AOSSs that disperse directly to ground water require quarterly samples and continuous monitoring of critical treatment units. Large AOSSs that disperse directly to ground water require monthly samples and 24-hour staffing or telemetry in order to continuously monitor critical treatment units;

v. Sampling and monitoring requirements for large AOSSs are enumerated in Table 4 of the regulations; and

w. Recommended field measurements, sampling, and observations for all AOSSs up to 0.04 MGD are enumerated in Table 5 of the regulations.

9. Operator responsibilities that include:

a. Filing a report with VDH for each required visit or when there is a reportable incident;

b. Accomplishing the various responsibilities and assessments required by the regulations using visual and other observations, laboratory and field tests deemed appropriate and as required by the regulations;

c. Keeping a log for each AOSS for which he is responsible; and

d. Notifying VDH when his relationship with an owner terminates.

10. A requirement that any person who pumps or otherwise removes sludge or solids from any septic tank or treatment unit of an AOSS must file a report with VDH.

11. The establishment of owner responsibilities that include:

a. Maintaining a relationship with an operator;

b. Having the AOSS operated and maintained by an operator;

c. Having the AOSS visited by an operator at the frequencies and times required by the regulations;

d. Having an operator collect all required samples;

e. Keeping a copy of the log provided by the operator and the operation and maintenance manual (O&M manual) and making a reasonable effort to transfer both to a new property owner; and

f. Complying with the onsite sewage system requirements contained in local ordinances adopted pursuant to the Chesapeake Bay Preservation Act (§ 10.1-2100 et. seq.) and the Chesapeake Bay Preservation Area Designation and Management Regulations (9VAC10-20) when an AOSS is located within a Chesapeake Bay Preservation Area.

12. AOSS with flows less than or equal to 1,000 gpd require one operator visit within the first six months after the operation permit is issued, and an annual visit thereafter. AOSS with flows that exceed 1,000 gpd require more frequent operator visits and staffing.

13. Each AOSS must have an O&M manual prepared by the designer and submitted to the local health department for approval.

14. Minimum expectations for operator visits include:

a. Inspecting all components of the AOSS, conducting field measurements, sampling, and other observations as required by the regulations or the O&M manual, or as deemed necessary by the operator to assess the performance of the AOSS and its components;

b. Performing routine maintenance, making adjustments, and replacing worn or dysfunctional components with in-kind parts such that the system can reasonably be expected to return to normal operation; and

c. If the AOSS is not functioning as designed or in accordance with the performance requirements of the regulations and, in the operators professional judgment it cannot be reasonably expected to return to normal function through routine operation and maintenance, then the operator must immediately report to the owner the remediation efforts necessary to return the AOSS to normal operation.

15. The establishment of the minimum reporting requirements whenever an operator is required to file a report, which include:

a. The name and license number of the operator, the date and time of the report, and the purpose of the visit;

b. A summary statement describing whether the AOSS is functioning as designed, whether the operator believes that routine maintenance performed will return the AOSS to normal operation, or whether additional actions are required to return the AOSS to normal operation;

c. A report of maintenance performed, field measurements, observations, and sampling; and the name of the laboratory that will analyze samples; and

d. A copy of the report provided to VDH and the owner.

16. Horizontal setbacks for AOSS designs under § 32.1-163.6 of the Code of Virgina, which are necessary to protect public health and the environment and which cannot be reduced by the engineer designing an AOSS under § 32.1-163.6 of the Code of Virgina.

The following is a change from the existing Sewage Handling and Disposal Regulations:

Current section number	Proposed new section number	Current requirement	Proposed change and rationale
12VAC5-950 Table 5.4	12VAC5-613-40	Table 5.4 contains prescriptive sizing criteria for soil absorption areas	This change applies only to AOSSs designed to disperse TL-2 or TL-3 effluent. These systems will be sized in accordance with performance requirements established in these regulations. Alternative systems that disperse septic tank effluent will continue to be sized in accordance with Table 5.4 of the Sewage Handling and Disposal Regulations. Because of the reduced organic loading rates and other benefits, AOSSs that treat wastewater to a higher degree than septic tank effluent before dispersal to a soil treatment area can utilize higher hydraulic loading rates than systems utilizing septic tank effluent.

Issues: The primary advantage to the public is providing access to adequate performance requirements, horizontal setbacks that protect public health, and operation and maintenance requirements for AOSSs. The proposed regulations also include nitrogen reduction requirements for all large AOSSs regardless of locality and small AOSSs located in the Chesapeake Bay Watershed. The public would enjoy more environmental protection with greater regulatory oversight. Less pollution and pathogens will better protect Virginia's natural resources, including the Chesapeake Bay.

Chapter 220 of the 2009 Acts of Assembly required the board to promulgate emergency regulations to establish performance requirements and horizontal setbacks for AOSSs necessary to protect public health and the environment and to establish operation and maintenance requirements consistent with the requirements for AOSSs contained in § 32.1-164 of the Code of Virginia. The emergency regulations expire April 6, 2011. To the extent the emergency regulations fostered protection of public health and the environment, such protection would be lost if these replacement regulations are not adopted.

The primary disadvantage could be considered to be the costs that AOSS owners would incur to achieve compliance with the regulations. See the Department of Planning and Budget's economic impact analysis for more information about the costs owners of AOSS would incur as a result of these regulations.

The primary advantage to VDH is having cogent, enforceable regulations. Without these regulations, VDH will not have enforceable requirements to protect public health and the environment with an adequate margin of safety. The Sewage Handling and Disposal Regulations provide inadequate performance, operation, and maintenance requirements for the protection of public health and the environment against the potentially injurious effects of malfunctioning or failing AOSS treatment systems. Additionally, the regulation implements requirements in § 32.1-164 A and I of the Code of Virginia and the legislative mandate contained in Chapter 220 of the 2009 Acts of Assembly.

The Department of Planning and Budget's Economic Impact Analysis:

Summary of the Proposed Amendments to Regulation. The proposed regulations 1) establish performance and horizontal setback requirements for alternative onsite sewage systems (AOSS); 2) require owners of AOSS to have a relationship with a licensed operator for operation and maintenance of the system; establish an inspection, sampling, and reporting frequency for AOSS; and establish a $1 fee for filing of inspection reports with the Virginia Department of Health; 3) establish nitrogen limitations for all large AOSS and reduce nutrient loads for small AOSS; 4) establish additional design and monitoring requirements for small and large AOSS that disperse effluent directly into the groundwater; and 5) provide that generally approved systems undergo a reevaluation after five years from the effective date of these regulations.

Result of Analysis. There is insufficient data to accurately compare the magnitude of the benefits versus the costs. Detailed analysis of the benefits and costs can be found in the next section.

Estimated Economic Impact. Chapter 515 of the 2008 Acts of Assembly mandated that treatment works designs from individuals licensed as professional engineers shall be accepted as long as they comply with standard engineering practices, performance requirements, and the horizontal setback requirements established by the Board of Health. The performance requirements in effect at that time were Sewage Handling and Disposal Regulations¹ (SHDR) which had two basic principles: a) no back-up into the dwelling and b) no effluent or sewage discharge onto the ground surface. After July 2008, Virginia Department of Health (VDH) started receiving applications with designs that otherwise complied with the performance requirements of the SHDR, but for the places that had historically been denied permits such as areas shallow to water table or rock and wetlands. In response, Chapter 220 of the 2009 Acts of Assembly directed VDH to implement emergency regulations which introduced additional performance requirements beyond SHDR.

In addition to the performance requirements contained in the emergency regulations, the proposed regulations contain additional performance requirements for cases where professional engineers propose sewage systems to disperse or discharge directly into groundwater or into wetlands. Under SHDR, VDH had been denying most proposals for direct dispersal into the groundwater.

While the proposed regulations also establish horizontal setback requirements for AOSS, these are the same standards enforced under the SHDR.

In short, when the statute mandated VDH to accept engineered designs for treatment works, the performance requirements contained in the SHDR were not adequate to minimize public health and environmental risks posed by the engineered systems. The proposed regulations introduce performance requirements that take into account potential risks posed by engineered systems.

One of the main economic effects of the proposed regulations arises from the fact that the sewage system permit has a direct impact on the feasibility of a building project and therefore the value of the underlying real property. In the absence of these regulations, VDH would be required to accept engineered systems shallow to water table or rock and wetlands as long as they complied with the performance requirements of SHDR. Since the proposed regulations introduce additional criteria compared to SHDR, they have the potential to make some of the previously feasible real estate development projects infeasible if the standards to protect public health and environment have not been met. On the other hand, VDH has been denying engineered systems designed to disperse or discharge directly into groundwater or into wetlands based on the interpretation that such a design is not a standard engineering practice. Since the proposed regulations allow systems designed to discharge into the groundwater so long as the standards to protect public health and environment have been met, they have the potential to make some of the previously infeasible real estate development projects feasible.

Considering, of the 1,500 to 2,700 alternative systems built every year, 25 to 300 are direct dispersal systems, the proposed performance standards are expected to make more feasible projects infeasible than making infeasible projects feasible. However, the proposed performance standards provide protection against the public health and environmental risks otherwise would have been posed by a large proportion of the alternative systems.

Chapter 220 of the 2009 Acts of Assembly also mandated that the Board of Health adopt regulations for operation and maintenance of the AOSS. The proposed regulations require that all AOSS owners must have a relationship with an operator, have the operator inspect their system once a year, report their findings with VDH, and collect samples for laboratory testing every five years for generally approved systems and every year for non-generally approved systems. VDH expects the cost of regular maintenance to be approximately $300 to $600 per year for generally approved small AOSS. The estimated maintenance cost for non-generally approved small AOSS range from $450 to $800 because of the increased sampling frequency. There are approximately 60,000 AOSS currently operating in Virginia and every year an additional 1,500 to 2,700 new systems come online. Approximately 60 to 80 percent of the systems are generally approved and the rest are non-generally approved. Thus, the statewide total cost of the proposed maintenance requirement for existing systems is expected to be between $10.8 million and $28.8 million for generally approved systems and $5.4 million and $19.2 million for non-generally approved systems. As more systems are installed, the statewide cost is expected to grow annually by $270,000 to $1.3 million for generally approved systems and by $243,000 to $480,000 for non-generally approved systems.

However, there have been several known localities² that were already requiring some type of maintenance or inspection. A survey conducted by the Weldon Cooper Center for Public Service³ indicates 39% of the respondents said that homeowners in their counties or localities were legally required to have their systems inspected, 35% said this was not the case, and the remaining 26% were not sure. Additionally, 39% of the AOSS owners surveyed had maintenance contracts in place and 77% said that they had had a routine maintenance performed on their system in the last five years. Furthermore, 84% of respondents with AOSS had their system inspected in the last year. Thus, a non-negligible portion of the AOSS owners had already been incurring maintenance and inspection costs for their systems prior to the proposed regulations and the additional costs on these owners will be smaller.

On the other hand, routine inspection and maintenance is expected to extend the operational life of the system indefinitely, reduce operational and equipment deficiencies, allow the operator to find out and respond more quickly to problems, and consequently reduce malfunction costs and the chances of total system failure and the need for system replacement. Additionally, routine inspection and maintenance is expected to reduce public health and environmental risks associated with a system failure.

The proposed regulations are also expected to have a significant effect on the operators. Since a relationship with an operator is required, an increase in demand for AOSS technical services is expected. However, as mentioned before some of the AOSS owners already have maintenance or inspection performed on their systems voluntarily or as required by their local government. Thus, the potential increase in their business revenues will be somewhat offset.

The proposed regulations are likely to introduce some administrative costs on VDH. Under the proposed regulations, VDH will develop an inventory of AOSS in Virginia, build an Internet-based report filing system for the annual inspection reports required, compare reports with the inventory, conduct random site inspections, and follow up with those who do not get their systems inspected annually. According to VDH approximately 10 to 24 full time positions will be devoted to ensure compliance with the new regulations, but the administrative resources will be shifted from other functions to meet this need.

Also, pursuant to Chapter 892 of the 2007 Acts of Assembly, the proposed regulations establish a $1 fee for filing of annual inspection reports. Since there are approximately 60,000 systems operating in Virginia, up to $60,000 in fees is expected to be collected annually from the licensed operators. These funds will help VDH offset some of its administrative costs discussed above.

Furthermore, the proposed regulations establish nitrogen limitations for small AOSS and reduce nutrient loads for large AOSS. All small AOSS in the Chesapeake Bay Watershed are required reduce total nitrogen by 50%. To achieve the required reduction, VDH estimates that small AOSS installation costs will increase by $2 to $10 per gallon of capacity depending on the site conditions due to the required changes in the design. For example, an AOSS designed for a three bedroom home at 450 gallon per day capacity is expected to incur an additional one-time $900 to $4,500 in installation and new equipment costs. Approximately 1,000 to 2,000 small AOSS are estimated to be installed in the Chesapeake Bay Watershed every year. Thus, statewide total cost to comply with new nitrogen limits for small AOSS owners may range from $900,000 to $9 million annually.

Large AOSS are required to reduce their nitrogen concentration from 5 mg/l to 3 mg/l. The estimated cost of the required design change to achieve the new standard is estimated to be between 10 cents to 75 cents per gallon of capacity depending on the type of technology chosen and site conditions. For example, a system designed to discharge 10,000 gallons per day may incur an additional $1,000 to $7,500 in one-time installation and new equipment costs to reduce nitrogen load. Approximately 20 large AOSS with an average capacity of 10,000 gallons per day are estimated to be installed in the Chesapeake Bay Watershed annually. Thus, statewide total cost to comply with new nitrogen limits for large AOSS owners may range from $20,000 to $150,000 annually.

The proposed regulations establish additional design and monitoring requirements for small and large AOSS that disperse effluent directly into the groundwater. The one-time additional costs to change the small AOSS design is estimated to be between $5,000 and $10,000 depending on the capacity of the system, technology chosen, and the site conditions. The costs associated with the additional monitoring of small AOSS are estimated to be between $800 and $2,500 per year. VDH estimates that there are 25 to 300 small AOSS coming online each year that disperse effluent directly into the groundwater. Thus, statewide one-time total annual design costs are expected to range from $125,000 to $3,000,000. The statewide costs for the additional monitoring costs may range from $20,000 to $750,000 in the first year and continually increase by about the same amount for each additional year as more systems built over time.

Similarly, the proposed regulations require additional monitoring and treatment including enhanced disinfection and nutrient reduction for large AOSS that disperse effluent directly into the groundwater. The one-time additional design costs to comply with the proposed changes are estimated to be $2 to $10 per gallon of capacity. VDH estimates there are approximately 10 large AOSS are built per year. If the average capacity of new systems is 10,000 gallons per day, then the statewide costs may range from $200,000 to $1 million every year. In addition, additional ongoing monitoring costs are expected, but VDH does not have good estimates for this type of costs. Statewide additional monitoring costs will accumulate over time as more systems are built.

The statewide costs for the additional monitoring costs may range from $20,000 to $750,000 in the first year and continually increase by about the same amount for each additional year as more systems are built over time.

The proposed regulations also provide that generally approved systems undergo a reevaluation after five years from the effective date of these regulations. Currently, there are seven manufacturers with a generally approved system. A reevaluation would require analysis of 80 observations per system at a cost of $300 to $400 per observation. Thus, the total cost to all seven manufacturers is estimated to be $168,000 to $224,000 or $24,000 to $32,000 per manufacturer five years later. VDH is likely to incur some administrative costs in order to conduct the proposed reevaluations. On the other hand, the proposed reevaluation will help make sure that the generally approved systems continue to meet performance standards.

The main benefit of the proposed regulations is to protect public health and environment. Improperly sited and designed systems may cause untreated sewage to move hundreds of feet away from a home contaminating the underground and surface waters threatening the public health. Organic matter, suspended solids, and nutrients may threaten streams, rivers, and lakes. Pollutants such as bacteria, viruses, and nitrate may threaten the public health. In the absence of the proposed performance standards and maintenance requirements, alternative sewage systems would pose health and environmental risks.

Businesses and Entities Affected. Currently, there are 60,000 AOSS systems, 545 licensed AOSS operators, and seven manufacturers with a generally approved system in Virginia.

Localities Particularly Affected. Some of the proposed regulations establish nitrogen limitations for AOSS located in the Chesapeake Watershed which includes all or parts of following localities: Frederick, Clarke, Loudoun, Shenandoah, Warren, Fauquier, Prince William, Fairfax, Rockingham, Page, Rappahannock, Culpeper, Stafford, Augusta, Greene, Madison, Orange, Albemarle, Spotsylvania, Louisa, Caroline, King George, Westmoreland, Essex, Richmond, Northumberland, Highland, Bath, Alleghany, Rockbridge, Nelson, Buckingham, Fluvanna, Goochland, Hanover, Henrico, King William, King and Queen, New Kent, Middlesex, Lancaster, Craig, Botetourt, Roanoke, Montgomery, Bedford, Amherst, Campbell, Appomattox, Cumberland, Prince Edward, Powhatan, Amelia, Nottoway, Chesterfield, Dinwiddie, Prince George, Charles City, James City, Surry, Gloucester, Matthews, York, Isle of Wight, Suffolk, Chesapeake, Accomack, and Northampton.

Rest of the proposed regulations applies throughout the Commonwealth. However, the survey conducted by the Weldon Cooper Center for Public Service⁴ reveals that 31.3% of the alternative systems surveyed are located in Northwest Virginia, 26.3% are located in Northern Virginia, 22.4% are located in Eastern Virginia, 18.5% are located in Central Virginia, and 4.6% are located in southwest Virginia.

Projected Impact on Employment. The proposed standards for direct dispersal systems appear to be less stringent than SHDR standards. Thus, they are expected to make some building projects that were infeasible under SHDR feasible. On the other hand, the proposed standards for the remaining AOSS and the nitrogen standards for the systems located in the Chesapeake Bay watershed appear to be more stringent than SHDR standards. Since AOSS systems that are not direct dispersal systems and the systems located in the Chesapeake Bay watershed has a wider applicability than the direct dispersal systems, the proposed regulations may reduce the number of feasible building projects and consequently the demand for labor.

On the other hand, the proposed regulations are expected to minimize public health and environmental risks posed by AOSS. Reduced public health and environmental risks are likely to promote tourism and commerce in the Commonwealth and increase demand for labor. Additionally, the demand for technical services of AOSS operators will add to the demand for labor.

Finally, the proposed regulations are expected to increase the need for additional staff at VDH to administer the program, but the increased demand will be offset by reductions in other functional areas within the VDH.

Effects on the Use and Value of Private Property. The proposed standards for direct dispersal systems appear to be less stringent than SHDR standards. Thus, they are expected to make some building projects that were infeasible under SHDR feasible. The values of such private properties are expected to increase as a result of the proposed regulations.

On the other hand, the proposed standards for the remaining AOSS and the nitrogen standards for the systems located in the Chesapeake Bay watershed appear to be more stringent than SHDR standards. The values of such private properties are expected to decrease as a result of the proposed regulations.

Additional operating and maintenance costs on AOSS owners may negatively affect demand for their houses which in turn may have a negative effect on the price of their houses. However, ensuring proper maintenance and operation is expected to extend the life of the system and may add to the value of the house.

In addition, the asset values of AOSS operator businesses are expected to increase due to the additional demand created for their services.

Finally, the proposed sunset provisions for the systems that are generally approved are expected to introduce costs associated with testing and consequently have a negative impact on the asset values of the affected manufacturers.

Small Businesses: Costs and Other Effects. The proposed regulations will introduce the same costs and affects discussed above to small businesses if they own an AOSS. The number of small businesses that own an AOSS is not known.

In addition, most of the AOSS operators are expected to be small businesses. The proposed regulations will have a positive impact on their revenues.

Small Businesses: Alternative Method that Minimizes Adverse Impact. There is no known alternative method that would minimize the adverse impact on small businesses that own an AOSS and achieve the same goals.

Real Estate Development Costs. The proposed standards for direct dispersal systems appear to be less stringent than SHDR standards. Thus, they are expected to make some development projects that were infeasible under SHDR feasible. The proposed regulations are expected to reduce the real estate development costs in these cases.

On the other hand, the proposed standards for the remaining AOSS and the nitrogen standards for the systems located in the Chesapeake Bay watershed appear to be more stringent than SHDR standards. The proposed regulations are expected to increase the real estate development costs in these cases.

Legal Mandate. The Department of Planning and Budget (DPB) has analyzed the economic impact of this proposed regulation in accordance with § 2.2-4007 H of the Administrative Process Act and Executive Order Number 14 (10). Section 2.2-4007 H requires that such economic impact analyses include, but need not be limited to, the projected number of businesses or other entities to whom the regulation would apply, the identity of any localities and types of businesses or other entities particularly affected, the projected number of persons and employment positions to be affected, the projected costs to affected businesses or entities to implement or comply with the regulation, and the impact on the use and value of private property. Further, if the proposed regulation has adverse effect on small businesses, § 2.2-4007 H requires that such economic impact analyses include (i) an identification and estimate of the number of small businesses subject to the regulation; (ii) the projected reporting, recordkeeping, and other administrative costs required for small businesses to comply with the regulation, including the type of professional skills necessary for preparing required reports and other documents; (iii) a statement of the probable effect of the regulation on affected small businesses; and (iv) a description of any less intrusive or less costly alternative methods of achieving the purpose of the regulation. The analysis presented above represents DPB's best estimate of these economic impacts.

_______________________________

¹ 12VAC5-610

² Known localities that used to require maintenance of AOSS include Loudoun County, Augusta County, and Gloucester County.

³ Survey of Alternative Onsite System Issues in Virginia, 2009, Weldon Cooper Center for Public Service.

⁴ Survey of Alternative Onsite System Issues in Virginia, 2009, Weldon Cooper Center for Public Service.

Agency's Response to the Department of Planning and Budget's Economic Impact Analysis: The agency concurs with the Department of Planning and Budget's (DPB) analysis that the proposed regulations are likely to impose economic costs and produce economic benefits. However, the risk to public health will be lessened from reduced pathogen concentrations as required by the proposed regulations. The agency also sees economic benefit to commercial fisheries, shellfish operations, tourism and recreation, property values, and the regional economies.

In May 1999, the Environmental Protection Agency (EPA) placed most of Virginia's Chesapeake Bay watershed and several of its associated tidal tributaries on the impaired waters list under § 3039(d) of the Clean Water Act because of excessive nutrient and sediment pollution. The 2000 Chesapeake Bay agreement¹ set a goal of removing these waters from the list of impaired water bodies. The water quality standards were not met as outlined in the 2000 agreement so EPA is in the process of establishing a federal Total Maximum Daily Load (TMDL) or "pollution diet" for the tidal segments of the Chesapeake Bay and its tidal tributaries. The TMDL will establish limits on the amount of nitrogen, phosphorus, and sediment that can enter the Chesapeake Bay from all source sectors, point and nonpoint. Onsite sewage systems are considered a nonpoint source sector of nitrogen pollution that contributes about 4.0% of the total nitrogen to the Chesapeake Bay each year, or about 2.9 million total pounds of nitrogen.

The Watershed Implementation Plan² (WIP), which outlines how Virginia intends to comply with the TMDL, would require Virginia to reduce nitrogen levels below present levels and account for growth of the population. Of the 500,000 to 600,000 onsite sewage systems being used in Virginia's portion of the Chesapeake Bay watershed, mostly at single-family residences, about 10%, or 60,000 systems, are estimated to be alternative onsite sewage systems impacted by the proposed regulations. Virginians install about 11,250 new onsite sewage systems on average in the watershed each year, including 1,500 to 2,700 alternative onsite sewage systems. Each new onsite sewage system contributes nitrogen and no technology can presently remove 100% of the nitrogen. The best available technology can achieve about 75% reduction at an estimated cost of $15,000 to $25,000 per system. The proposed regulations require a 50% reduction for alternative onsite sewage systems installed in the Chesapeake Bay watershed (not conventional systems). VDH estimates that this requirement will cost $2.00 to $10.00 per gallon, or about $900 to $4,500 per single family dwelling.

The limits proposed by the regulations will not reduce nitrogen in sufficient quantities to meet the anticipated WIP and TMDL as calculated through EPA's modeling of pollution from the onsite sewage system source sector. The proposed nitrogen reductions only slow the rate of nutrient impacts from onsite sewage systems. Current versions of the WIP propose an expansion of the nutrient credit exchange program to include offsets from the onsite sewage system sector. By slowing the rate of increase in nitrogen from onsite sewage systems, the proposed regulations may reduce the amount of credits that would have to be purchased.

In 2004, the State Water Control Board, Department of Environmental Quality (DEQ) proposed regulations to reduce nutrient and sediment pollution to the Chesapeake Bay watershed from point source discharges (9VAC25-40, Policy for Nutrient Enriched Waters; and 9VAC25-720, Water Quality Management Regulation). DPB cited numerous studies and information about the economic benefits of reducing nutrient and sediment pollution in its review of these regulations, which can be viewed at http://www.townhall.state.va.us/L/GetFile.cfm?File=E:\townhall\docroot\103\1389\2911\EIA_DEQ_2911_v2.pdf). DEQ's response can be viewed at the following link:

http://www.townhall.state.va.us/L/GetFile.cfm?File=E:\townhall\docroot\103\1389\2911\EIARes_DEQ_2911_v1.pdf.

DPB reported insufficient data to adequately compare benefits and costs for the proposed regulations. VDH believes the economic benefits and studies used in DPB's analysis from 2004 for point source nutrient reductions could also be used as a reference for the proposed regulations, which address a nonpoint source.

The nitrogen reductions proposed by this regulation should be considered as part of the Commonwealth's overall strategy to meet the WIP and TMDL. While VDH is not aware of any specific study or analysis comparing the costs for pounds of nitrogen removed from each source sector, economies of scale would dictate that the cost to remove each pound of nitrogen from other source sectors, such as wastewater treatment plants, would deliver more nitrogen removal per dollar of cost. Presently, each single family home is expected on average to deliver about 9.8 lbs per year of nitrogen to the Chesapeake Bay according to the EPA model. The cost for a 50% reduction in pounds of nitrogen (4.9 lbs/year) is expected to be about $900 to $4,500 per single family home. The cost per pound of nitrogen removed from other source sectors with bigger economies of scale would be expected to cost significantly less on a relative basis.

To achieve an overall reduction in nitrogen within the onsite sewage system source sector and account for growth, some number of existing systems would need to be retrofitted with nitrogen-reducing technologies. The proposed regulations do not affect 85 to 90% of the onsite sewage systems in the Chesapeake Bay watershed. If overall nutrient reductions cannot be achieved within the onsite sewage system sector, then offsets would have to be obtained from another source sector or sectors. At present there are no mechanisms in place that would allow individual homeowners to trade nutrient credits, nor is there any source of funding to assist owners in installing nitrogen-reducing technologies. Regardless of any future strategy employed, obtaining an overall reduction in nitrogen from onsite sewage systems based on EPA's current model will be difficult and expensive. Significant statutory and regulatory changes as well as changes in funding options for onsite sewage systems would have to be proposed.

VDH's current approach to controlling nitrogen, given its present authority, focuses on requiring nitrogen reduction for large alternative (cluster) systems; encouraging design practices that favor nitrogen reduction for small systems; requiring operation, maintenance, and inspection of all alternative system; and increasing the accuracy of the database to account for the voluntary uses of nitrogen-reducing technologies.

_________________________

¹ Pennsylvania, Maryland, Virginia, Washington, D.C., the Chesapeake Bay Commission, and EPA signed the agreement. In a separate six-state memorandum of understanding with EPA, New York, Delaware, and West Virginia also made the same commitment.

² Visit http://www.deq.virginia.gov/tmdl/baywip.html for more information about the WIP.

Summary:

The proposed regulatory action creates an inspection, sampling, and reporting frequency for all alternative onsite sewage systems (AOSS). The proposed regulations (i) establish the performance requirements for AOSS, as well as horizontal setbacks for those designed in accordance with § 32.1-163.6 of the Code of Virginia; (ii) require owners to have a relationship with a licensed operator for the purpose of providing operation and maintenance to the AOSS; (iii) establish nitrogen limitations for all large AOSS and require all small AOSS to reduce nutrient loads within the Chesapeake Bay Watershed; (iv) establish treatment levels for performance and provide a methodology for evaluating treatment unit efficacy; and (v) supplement the existing Sewage Handling and Disposal Regulations (12VAC5-610-20) that contain permitting and enforcement procedures and other requirements for onsite sewage systems, including AOSS.

CHAPTER 613
REGULATIONS FOR ALTERNATIVE ONSITE SEWAGE SYSTEMS

Part I
General

12VAC5-613-10. Definitions.

The following words and terms used in this chapter shall have the following meanings. Terms not defined in this chapter shall have the meanings prescribed in Chapter 6 (§ 32.1-163 et seq.) of Title 32.1 of the Code of Virginia or in 12VAC5-610 unless the plain reading of the language requires a different meaning.

"Alternative onsite sewage system," "AOSS," or "alternative onsite system" means a treatment works that is not a conventional onsite sewage system and does not result in a point source discharge.

"Best management practice" means a conservation or pollution control practice approved by the division, such as wastewater treatment units, shallow effluent dispersal fields, saturated or unsaturated soil zones, or vegetated buffers, that manages nutrient losses or other potential pollutant sources to minimize pollution of water resources.

"Biochemical oxygen demand" or "BOD" means the measure of the amount of oxygen required by bacteria for stabilizing material that can be decomposed under aerobic conditions.

"Biochemical oxygen demand, five-day" or "BOD₅" means the quantitative measure of the amount of oxygen consumed by bacteria while stabilizing, digesting, or treating biodegradable organic matter under aerobic conditions over a five-day incubation period; BOD₅ is expressed in milligrams per liter (mg/l).

"Board" means the State Board of Health.

"Chesapeake Bay Watershed" means the following Virginia river basins: Potomac River Basin (see 9VAC25-260-390 and 9VAC25-260-400), James River Basin (see 9VAC25-260-410, 9VAC25-260-415, 9VAC25-260-420, and 9VAC25-260-430), Rappahannock River Basin (see 9VAC25-260-440), Chesapeake Bay and small coastal basins (see 9VAC25-260-520, Section 2 through Section 3g), and the York River Basin (see 9VAC25-260-530).

"Conventional onsite sewage system" means a treatment works consisting of one or more septic tanks with gravity, pumped, or siphoned conveyance to a gravity distributed subsurface drainfield.

"Department" means the Virginia Department of Health.

"Direct dispersal of effluent to ground water" means less than six inches of vertical separation between the point of effluent application or the bottom of a trench or other excavation and ground water.

"Disinfection" means a process used to destroy or inactivate pathogenic microorganisms in wastewater to render them non-infectious.

"Dissolved oxygen" or "DO" means the concentration of oxygen dissolved in effluent, expressed in mg/l or as percent saturation, where saturation is the maximum amount of oxygen that can theoretically be dissolved in water at a given altitude and temperature.

"Division" means the Division of Onsite Sewage and Water Services, Environmental Engineering, and Marina Programs within the department or equivalent.

"Effluent" means sewage that has undergone treatment.

"General approval" means that a treatment unit has been evaluated and approved for TL-2 or TL-3 in accordance with the requirements of this chapter.

"GPD/sf" means gallons per day per square foot.

"Ground water" means any water, except capillary moisture, beneath the land surface in the zone of saturation or beneath the bed of any stream, lake, reservoir, or other body of surface water wholly or partially within the boundaries of this Commonwealth, whatever the subsurface geologic structure in which such water stands, flows, percolates, or otherwise occurs. Ground water includes a seasonal or perched water table.

"High-level disinfection" means a disinfection method that results in a fecal coliform concentration less than or equal to 2.2 colonies/100 ml. Chlorine disinfection requires a minimum total residual chlorine (TRC) concentration at the end of a 30 minute contact time of 1.5 mg/l. Ultraviolet disinfection requires a minimum dose of 50,000 μW-sec/cm². Influent turbidity to the disinfection unit shall be less than or equal to 2 Nephelometric turbidity units (NTU) on average.

"Ksat" means saturated hydraulic conductivity.

"Large AOSS" means an AOSS that serves more than three attached or detached single-family residences or a structure with an average daily sewage flow in excess of 1,000 gpd.

"Limiting feature" means a feature of the soil that limits or intercepts the vertical movement of water, including seasonal, perched or permanent water table, pans, soil restrictions, and pervious or impervious bedrock.

"Local health department" means the local health department having jurisdiction over the AOSS.

"Maintenance" means performing adjustments to equipment and controls and in-kind replacement of normal wear and tear parts such as light bulbs, fuses, filters, pumps, motors, or other like components. Maintenance includes pumping the tanks or cleaning the building sewer on a periodic basis. Maintenance shall not include replacement of tanks, drainfield piping, and distribution boxes or work requiring a construction permit and an installer.

"MGD" means million gallons per day.

"MPI" means minutes per inch.

"Operate" means the act of making a decision on one's own volition to (i) place into or take out of service a unit process or unit processes or (ii) make or cause adjustments in the operation of a unit process at a treatment works.

"Operation" means the biological, chemical, and mechanical processes of transforming sewage or wastewater to compounds or elements and water that no longer possess an adverse environmental or health impact.

"Operator" means any individual employed or contracted by any owner who is 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, monitor, and maintain an alternative onsite sewage system.

"Organic loading rate" means the biodegradable fraction of chemical oxygen demand (BOD, biodegradable fats, oils, and grease and volatile solids) delivered to a treatment component in a specified time interval expressed as mass per time or area; examples include pounds per day, pounds per cubic foot per day (pretreatment), or pounds per square foot per day (infiltrative surface or pretreatment). For a typical residential system, these regulations assume that biochemical loading (BOD₅) equals organic loading.

"Owner" means the Commonwealth or any of its political subdivisions, including sanitary districts, sanitation district commissions and authorities, or any individual, any group of individuals acting individually or as a group, or any public or private institution, corporation, company, partnership, firm, or association that owns or proposes to own a sewerage system or treatment works.

"pH" means the measure of the acid or base quality of water that is the negative log of the hydrogen ion concentration.

"Pollution" means such alteration of the physical, chemical, or biological properties of any state waters as will or is likely to create a nuisance or render such waters (i) harmful or detrimental or injurious to the public health, safety, or welfare or to the health of animals, fish, or aquatic life; (ii) unsuitable with reasonable treatment for use as present or possible future sources of public water supply; or (iii) unsuitable for recreational, commercial, industrial, agricultural, or other reasonable uses. Pollution shall include any discharge of untreated sewage into state waters.

"Project area" means one or more recorded lots or a portion of a recorded lot owned by the owner of an AOSS or controlled by easement upon which an AOSS is located or that is contiguous to a soil treatment area and that is designated as such for purposes of compliance with the performance requirements of this chapter. In the case of an AOSS serving multiple dwellings, the project area may include multiple recorded lots as in a subdivision.

"Project area boundary" means the limits of the three-dimensional space defined when (i) the horizontal component is the project area; (ii) the upper vertical limit is the ground surface in and around the AOSS; and (iii) the lower vertical limit is the vertical separation required by this chapter, a permeability limiting feature, or the permanent water table.

"Relationship with an operator" means an agreement between the owner of an AOSS and operator wherein the operator has been retained by the owner to operate the AOSS in accordance with the requirements of this chapter.

"Renewable operating permit" means an operation permit that expires and must be revalidated at a predetermined frequency or schedule in accordance with this chapter.

"Reportable incident" means one or more of the following: an alarm event; any failure to achieve one or more performance requirements; removal of solids; replacement of media; or replacement of any major component of the system including electric and electronic components, pumps, blowers, and valves. The routine maintenance of effluent filters is not a reportable incident.

"Saturated hydraulic conductivity" means a quantitative measure of a saturated soil's capacity to transmit water when subjected to a hydraulic gradient.

"Settleable solids" means a measure of the volume of suspended solids that will settle out of suspension within a specified time, expressed in milliliters per liter (ml/l).

"Sewage Handling and Disposal Regulations" means 12VAC5-610 adopted by the board.

"Small AOSS" means an AOSS that serves no more than three attached or detached single-family residences or a structure with an average daily sewage flow of less than or equal to 1,000 gpd.

"Soil treatment area" means the physical location in or on the naturally-occurring soil medium where final treatment and dispersal of effluent occurs; the soil treatment area includes subsurface drainfields and drip dispersal fields.

"Standard disinfection" means a disinfection process that results in a fecal coliform concentration of less than or equal to 200 colonies/100 ml. Chlorine disinfection requires a minimum TRC concentration at the end of a 30 minute contact time of 1.0 mg/l. Influent TSS to the disinfection unit shall average 30 mg/l or less.

"Standard engineering practice" means the care, diligence, competence, and judgment that a reasonably prudent and experienced professional engineer licensed in the Commonwealth of Virginia would exercise given the circumstances, including site and soil conditions, of a particular AOSS design.

"State waters" means all water, on the surface and under the ground, wholly or partially within or bordering the Commonwealth or within its jurisdiction, including wetlands.

"Subsurface drainfield" means a system installed within the soil and designed to accommodate treated sewage from a treatment works.

"Total nitrogen" or "TN" means the measure of the complete nitrogen content of wastewater including all organic, inorganic, and oxidized forms expressed in mg/l as nitrogen.

"Total residual chlorine" or "TRC" means a measurement of the combined available chlorine and the free available chlorine available in a sample after a specified contact time.

"Total suspended solids" or "TSS" means a measure of the mass of all suspended solids in a sample typically measured in milligrams per liter (mg/l).

"Treatment level 2 effluent" or "TL-2 effluent" means effluent that has been treated to produce BOD₅ and TSS concentrations equal to or less than 30 mg/l each.

"Treatment level 3 effluent" or "TL-3 effluent" means effluent that has been treated to produce BOD₅ and TSS concentrations equal to or less than 10 mg/l each.

"Treatment unit" or "treatment system" means a method, technique, equipment, or process other than a septic tank or septic tanks used to treat sewage to produce effluent of a specified quality before the effluent is dispersed to a soil treatment area.

"Turbidity" means a measurement of the relative clarity of effluent as a result of the presence of varying amounts of suspended organic and inorganic materials or color.

"Vertical separation" means the vertical distance between the point of effluent application to the soil or the bottom of a trench or other excavation and a limiting feature of the soil treatment area such as seasonal high ground water, bedrock, or other restriction.

"Wetlands" means those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas and as otherwise identified by the Army Corps of Engineers.

12VAC5-613-20. Purpose and authority.

A. Pursuant to the requirements of §§ 32.1-12 and 32.1-163 of the Code of Virginia, the board has promulgated this chapter to:

1. Establish a program for regulating the operation and maintenance of alternative onsite sewage systems;

2. Establish performance requirements for alternative onsite sewage systems;

3. Establish horizontal setbacks for alternative onsite sewage systems that are necessary to protect public health and the environment;

4. Discharge the board's responsibility to supervise and control the safe and sanitary collection, conveyance, transportation, treatment, and disposal of sewage by onsite sewage systems and treatment works as they affect the public health and welfare;

5. Protect the quality of surface water and ground water;

6. Guide the commissioner in determining whether a permit or other authorization for an alternative onsite sewage system shall be issued or denied; and

7. Inform owners, applicants, onsite soil evaluators, system designers, and other persons of the requirements for obtaining a permit or other authorization for an AOSS.

B. The division may, as it deems necessary, develop best management practices for the purposes of recognizing acceptable methods to reduce pollution from AOSSs.

12VAC5-613-30. Applicability and scope.

A. As provided in this section, this chapter governs the design, construction, and operation of AOSSs.

B. Part II of this chapter, Performance Requirements, applies only to AOSSs with applications filed on or after the effective date of this chapter.

C. Any AOSS with an application filed prior to the effective date of this chapter is subject to the performance requirements contained in the regulations in effect at the time the system was permitted or the performance requirements contained in the operation permit.

D. Small AOSSs designed, constructed, permitted, and operated in accordance with this chapter; the prescriptive design, location, and construction criteria of 12VAC5-610-20; and the policies and procedures of the department are presumed to comply with the ground water quality requirements of 12VAC5-610-90 A.

E. Part III of this chapter, Operation and Maintenance Requirements, shall apply to all AOSSs, including those with applications filed prior to the effective date of this chapter.

F. Requirements for renewable operation permits contained in this chapter shall apply only to AOSSs with applications filed on or after the effective date of this chapter.

G. The laboratory sampling requirements of this chapter apply only to AOSSs with applications filed on or after the effective date of this chapter.

H. Any AOSS with an application filed prior to the effective date of this chapter is subject to the laboratory sampling requirements contained in the regulations in effect at the time the system was permitted or the sampling requirements contained in the operation permit.

I. AOSSs designed pursuant to § 32.1-163.6 of the Code of Virginia are subject to the following requirements:

1. Performance requirements of this chapter;

2. Horizontal setback requirements of this chapter;

3. Operation, maintenance, inspection, and sampling requirements of this chapter; and

4. Standard engineering practice.

J. Dispersal of treated or untreated sewage to a wetland is subject to permitting by the Virginia Department of Environmental Quality pursuant to the requirements of Title 62.1 of the Code of Virginia and is specifically excluded from this chapter.

K. Spray irrigation systems are subject to permitting by the Virginia Department of Environmental Quality and are specifically excluded from this chapter.

L. Treatment units for small AOSSs that are recognized by the department as generally approved for TL-2 or TL-3 as of the effective date of this chapter shall retain such status for a period of five years from the effective date of this chapter after which the units shall be evaluated pursuant to the requirements of this chapter.

M. After the effective date of this chapter, new applications for general approval for TL-2 or TL-3 shall be subject to the requirements of this chapter. The department may continue to evaluate any treatment unit for small AOSSs that is undergoing evaluation as of the effective date of this chapter using the protocol in place on the date of application for general approval.

12VAC5-613-40. Relationship to other regulations.

A. This chapter is supplemental to 12VAC5-610 (Sewage Handling and Disposal Regulations).

B. All procedures pertaining to enforcement, minimum requirements for filing applications, and processing of applications, including appeals and case decisions contained in the Sewage Handling and Disposal Regulations shall apply to the permitting of AOSSs under this chapter.

C. In any case where there is a conflict between this chapter and the Sewage Handling and Disposal Regulations, this chapter shall be controlling.

D. This chapter supersedes Table 5.4 of the Sewage Handling and Disposal Regulations for all AOSSs designed to disperse TL-2 or TL-3 effluent. Table 5.4 of the Sewage Handling and Disposal Regulations shall govern the design of any AOSS designed to disperse septic tank effluent to the soil treatment area.

E. In accordance with standard engineering practice, all plans and specifications for AOSSs shall be properly sealed by a professional engineer licensed in the Commonwealth pursuant to Title 54.1 of the Code of Virginia unless such plans are prepared pursuant to an exemption from the licensing requirements of Title 54.1 of the Code of Virginia. AOSS designs submitted pursuant to § 32.1-163.6 of the Code of Virginia shall have a statement on the title page of the plans clearly identifying the plans as a § 32.1-163.6 submittal. Where this statement is not included on the title page, the department will review the plans pursuant to the Sewage Handling and Disposal Regulations and applicable policies.

F. When AOSS designs are prepared pursuant to an exemption from the licensing requirements of Title 54.1 of the Code of Virginia, the designer shall provide a certification statement in a form approved by the division identifying the specific exemption under which the plans and specifications were prepared and certifying that the designer is authorized to prepare such plans pursuant to the exemption.

G. In accordance with standard engineering practice, each application under § 32.1-163.6 of the Code of Virginia shall include a site characterization report using the Field Book for Describing and Sampling Soils, Version 2.0, National Soil Survey Center, Natural Resources Conservation Service, U.S. Department of Agriculture, September 2002. The report may contain such information that the designer deems appropriate; however, it must describe the following minimum attributes of the site of the proposed soil treatment area:

1. Depth to limiting features, including seasonal or perched water tables, pans, restrictions, or pervious or impervious bedrock;

2. Slope of the project area;

3. Ksat or percolation rate at the proposed installation depth and at depths below the soil treatment area to demonstrate compliance with this chapter. Ksat or percolation rate may be estimated for small AOSSs. The Ksat or percolation rate must be measured using an appropriate device for large AOSSs;

4. Landscape or landform; and

5. Project area along with those physical features in the vicinity of the proposed AOSS normally associated with plans for onsite sewage systems; such physical features include streams, bodies of water, roads, utilities, wells and other drinking water sources, existing and proposed structures, and property boundaries.

12VAC5-613-50. Violations and enforcement.

A. Failure by any AOSS to achieve one or more performance requirements prescribed by this chapter shall be a violation of this chapter.

B. Failure by any owner, operator, or person to comply with the conditions of an operation permit shall be a violation of this chapter.

C. Failure by any owner, operator, or person to accomplish any mandated visit, operation, maintenance, repair, monitoring, sampling, reporting, or inspection requirement prescribed by this chapter shall be a violation of this chapter.

D. Failure to follow the approved operation and maintenance manual (O&M manual) shall be deemed a violation of this chapter when such failure results in the failure to achieve one or more performance requirements prescribed by this chapter.

E. Nothing in this chapter shall be construed to limit the authority of the board, the commissioner, or the department to enforce this chapter or to enforce the requirements of 12VAC5-610.

F. In accordance with the Sewage Handling and Disposal Regulations and § 32.1-25 of the Code of Virginia, the commissioner may take such samples and conduct such monitoring, including ground water samples and monitoring, that he deems necessary to enforce this chapter.

G. The board, commissioner, and department may use any lawful means to enforce this chapter including voiding a construction or operation permit, imposition of civil penalties, or criminal prosecution pursuant to § 32.1-27 of the Code of Virginia.

12VAC5-613-60. Operation permits and land records.

A. The department shall not issue an operation permit for an AOSS unless the owner has established a relationship with an operator and provided the operator's name and license number to the local health department. The owner shall maintain a relationship with an operator during all periods when the AOSS is in operation.

B. The department shall not issue an operation permit for an AOSS until the owner has recorded an instrument that complies with § 15.2-2157 E of the Code of Virginia in the land records of the circuit court having jurisdiction over the site of the AOSS.

C. When all or part of the project area is to be used in the management of nitrogen from a large AOSS, the owner shall record legal documentation in the land records of the circuit court having jurisdiction over the site of the AOSS. Such documentation shall be in a form approved by the division and shall protect and preserve the land area in accordance with the management methods established by the designer.

D. All large AOSSs and any AOSS permitted pursuant to 12VAC5-613-90 C shall be subject a renewable operating permit. Such permits shall be issued for a period of five years. Owners shall be required to apply for a new permit at least 180 days prior to the expiration date.

12VAC5-613-70. General approval testing and evaluation.

The division shall develop a protocol to verify the expected performance of treatment units of small AOSSs that meet TL-2 or TL-3 effluent quality. The protocol to evaluate and test field performance of TL-3 treatment units shall include the following minimum requirements:

1. The manufacturer shall evaluate at least 20 treatment units installed in the Commonwealth of Virginia for single family residences occupied full-time, year-round throughout the testing and evaluation period;

2. The manufacturer shall provide the division with quarterly results of influent and effluent samples measuring, at a minimum, BOD and TSS for each installed treatment unit;

3. Operation and maintenance shall be performed on each treatment unit during the evaluation period in accordance with the provisions of this chapter; and

4. An independent third party with no stake in the outcome of the approval process shall oversee and administer the testing and evaluation protocol. Examples of an independent third party include faculty members in an appropriate program of an accredited college or university, a licensed professional engineer experienced in the field of environmental engineering, or a testing firm that is deemed by the division to be acceptable.

Part II
Performance Requirements

12VAC5-613-80. Performance requirements; general.

All AOSS designed, constructed, and operated pursuant to this chapter shall comply with the following performance requirements:

1. The presence of raw or partially treated sewage on the ground's surface or in adjacent ditches or waterways is prohibited;

2. The exposure of insects, animals, or humans to raw or partially treated sewage is prohibited;

3. The backup of sewage into plumbing fixtures is prohibited;

4. The direct dispersal of effluent into ground water shall comply with 12VAC5-613-90 C;

5. All treatment units and treatment systems shall be designed for the anticipated wastewater strength and peak flow;

6. Dosing of the treatment unit or treatment system shall accommodate the design peak flow within the treatment unit's rated capacity;

7. The dispersal of septic tank effluent is prohibited for large AOSSs;

8. The AOSS shall be designed so that all components are of sufficient structural integrity to minimize the potential of physical harm to humans and animals;

9. The conveyance system for any AOSS shall be designed and installed with sufficient structural integrity to resist inflow and infiltration and to maintain forward flow;

10. The AOSS shall be designed to minimize noise, odor, or other nuisances at the property boundary;

11. Maximum trench bottom hydraulic loading rates for pressure-dosed systems using TL-2 and TL-3 effluent are found in Table 1 and are to be used as follows:

a. The designer is responsible for reducing loading rates according to the features and properties of the soils in the soil treatment area as well as for reducing loading rates for other types of dispersal;

b. Adherence to the maximum sizing criteria herein does not assure or guarantee that other performance requirements of this chapter, including effluent dispersal or ground water quality, will be met. It is the designer's responsibility to ensure that the proposed design is adequate to achieve all performance requirements of this chapter;

c. Trench bottom hydraulic loading rates for pressure-dosed systems shall not exceed the values in Table 1;

d. Trench bottom hydraulic loading rates shall be reduced from the values in Table 1 when a treatment unit or system is not designed to achieve TL-2 or TL-3. In such cases, the designer shall, for monitoring purposes, specify the effluent quality of the treatment unit. If the specified BOD₅ exceeds 60 mg/l, the designer shall use loading rates for septic tank effluent;

e. Trench bottom hydraulic loading rates for gravity dosed systems shall be reduced from the values in Table 1; and

f. Area hydraulic loading rates for systems such as drip dispersal, pads, spray irrigation, and mounds shall be reduced from the values in Table 1 and shall reflect standard engineering practice.

Table 1 Maximum Pressure-Dosed Trench Bottom Hydraulic Loading Rates
Percolation Rate (MPI)	TL-2 Effluent (gpd/sf)	TL-3 Effluent (gpd/sf)
≤15	1.8	3.0
15 to 25	1.4	2.0
>25 to 45	1.2	1.5
>45 to 90	0.8	1.0
>90	0.4	0.5

12. Septic tank effluent may only be discharged to a soil treatment area when the vertical separation to a limiting feature consists of at least 18 inches of naturally-occurring, in-situ soil. AOSSs designed to disperse septic tank effluent require at least 12 inches of soil cover over the soil treatment area;

13. Adequate vertical separation shall be maintained to ensure the performance requirements of this chapter. Adequate vertical separation shall be demonstrated as follows:

a. For any small AOSS where the vertical separation to a permeability-limiting feature is less than 18 inches below the point of effluent application or the bottom of the trench or other excavation, or where the vertical separation to ground water is less than six inches in the naturally-occurring soil, the designer shall demonstrate that (i) the site is not flooded during the wet season, (ii) there is a hydraulic gradient sufficient to move the applied effluent off the site, and (iii) water mounding will not adversely affect the functioning of the soil treatment area or create ponding on the surface;

b. For any large AOSS regardless of site constraints, the designer shall demonstrate that (i) the site is not flooded during the wet season, (ii) there is a hydraulic gradient sufficient to move the applied effluent off the site, and (iii) water mounding will not adversely affect the functioning of the soil treatment area or create ponding on the surface;

c. For large AOSSs, the department may require the owner to monitor the degree of saturation beneath the soil treatment area; and

d. For any system in which artificial drainage is proposed as a method to meet the requirements of this chapter, the designer shall provide calculations and other documentation sufficient to demonstrate the effectiveness of the proposed drainage.

14. The following minimum effluent quality shall be met for the described vertical separation to limiting feature as measured from the point of effluent application or the bottom of the trench or other excavation:

Table 2 Minimum Effluent Requirements for Vertical Separation to Limiting Features
Vertical separation	Minimum Effluent Quality
≥18" (requires naturally occurring, undisturbed soils)	Septic
<18" to 12" (requires minimum 6" of naturally occurring, undisturbed soils)	TL-2
0" to <12"	TL-3 and standard disinfection*

*Note: Where direct dispersal of effluent to ground water occurs, effluent quality shall be governed by 12VAC5-613-90 C.

15. The organic loading rate shall not exceed 2.1 x 10^-4 BOD lb/day/sf on a trench-bottom basis; and

16. The designer shall specify methods and materials that will achieve the performance requirements of this chapter whenever sand, soil, or soil-like material is used to increase the vertical separation.

12VAC5-613-90. Performance requirements; ground water protection.

A. The AOSS shall not pose a greater risk of ground water pollution than systems otherwise permitted pursuant to 12VAC5-610. After wastewater has passed through a treatment unit or septic tank and through the soil in the soil treatment area, the concentration of fecal coliform organisms shall not exceed 2.2 cfu/100 ml at the lower vertical limit of the project area boundary.

B. Each large AOSS shall comply with TN limit of 5 mg/l at the project area boundary. Prior to the issuance of a construction permit, the designer shall demonstrate compliance with this requirement through modeling or other calculations. Such demonstration may incorporate multiple nitrogen removal methods such as pretreatment, vegetative uptake (only for AOSSs with shallow soil treatment areas), denitrification, and other viable nitrogen management methods. Ground water and other monitoring may be required at the department's discretion.

C. AOSSs with direct dispersal of effluent to ground water are subject to the following requirements:

1. If the concentration of any constituent in ground water is less than the limits set forth at 9VAC25-280, the natural quality for the constituent shall be maintained; natural quality shall also be maintained for all constituents not set forth in 9VAC25-280. If the concentration of any constituent in ground water exceeds the limit in the standard for that constituent, no addition of that constituent to the naturally occurring concentration shall be made. The commissioner shall consult with the Department of Environmental Quality prior to granting any variance from this subsection.

2. Ground water and laboratory sampling in accordance with 12VAC5-613-100 G.

3. The treatment unit or system shall comply with the following at a minimum:

a. The effluent quality from the treatment unit or system shall be measured prior to the point of effluent application to the soil treatment area and shall be as follows: BOD₅ and TSS concentrations each equal to or less than 5 mg/l; fecal coliform concentrations less than or equal to 2.2 col/100 ml as a geometric mean with no single sample exceeding 14 col/100 ml; TN of concentration of less than 5 mg/l, except in the Chesapeake Bay Watershed where the TN concentration shall be less than or equal to 3 mg/l; and total phosphorus concentration of less than 1 mg/l, except in the Chesapeake Bay Watershed where the total phosphorus concentration shall be less than or equal to 0.3 mg/l;

b. High level disinfection is required; and

c. Treatment systems shall incorporate filtration capable of demonstrating compliance with an average turbidity of less than or equal to 2 NTU prior to disinfection.

4. Gravity dispersal to the soil treatment area is prohibited.

5. Loading rates to the soil treatment area shall not exceed the loading rates in Table 1 of this section.

6. A renewable operating permit shall be obtained and maintained in accordance with 12VAC5-613-60 D.

7. The designer shall provide sufficient hydrogeologic analysis to demonstrate that a proposed AOSS will function as designed for the life of the structure served without degradation of the soil treatment area. This shall include a determination of ground water flow direction and rate.

D. The following additional nutrient requirements apply to all AOSSs in the Chesapeake Bay Watershed:

1. All small AOSSs shall provide a 50% reduction of TN as compared to a conventional gravity drainfield system; compliance with this subdivision may be demonstrated through the following:

a. Compliance with one or more best management practices approved by the division; or

b. Relevant and necessary calculations provided to show one or both of the following:

(1) Effluent TN concentration of 20 mg/l measured prior to application to the soil dispersal field; or

(2) A mass loading of 4.5 lbs N or less per person per year at the project boundary provided that no reduction for N is allotted for uptake or denitrification for the dispersal of effluent below the root zone (>18 inches below the soil surface).

2. All large AOSSs shall demonstrate less than 3 mg/l TN at the project boundary. Dilution may not be used to demonstrate compliance with this subdivision. At a minimum, the treatment system shall provide for the following effluent quality prior to application to the soil dispersal field:

Table 3 Maximum TN Effluent Quality Requirements for Large AOSSs
Design Flow	Maximum Total Nitrogen Effluent Concentration from Treatment System as TN
>1000 gpd to 40,000 gpd	20 mg/l
> 40,000 gpd to 100,000 gpd	10 mg/l
>100,000 gpd	5 mg/l

3. Ground water and other monitoring may be required at the department's discretion for large AOSSs.

E. No portion of an AOSS soil treatment area may be located in a wetland. Other portions of an AOSS may be located in wetlands subject to approval or permitting, as appropriate, by the Virginia Department of Environmental Quality.

12VAC5-613-100. Performance requirements; laboratory sampling and monitoring.

A. Laboratory sampling is not required for any small AOSS with an installed soil treatment area that is sized for septic tank effluent and complies with the requirements of 12VAC5-610 for septic tank effluent.

B. All effluent samples must be taken at the end of all treatment, prior to the point where the effluent is discharged to the soil treatment area. The designer shall identify the sampling points. When required, the sampling point for chlorine disinfection shall be at the end of the chlorine contact tank if TRC is to be used to measure compliance.

C. All sampling and monitoring shall be conducted according to procedures approved under 40 CFR Part 136 or alternative methods approved by the U.S. Environmental Protection Agency unless other procedures have been specified in this chapter.

D. The owner of each small AOSS is required to submit an initial grab sample of the effluent from the treatment unit and have the sample analyzed in accordance with 40 CFR Part 136 or alternative methods approved by the U.S. Environmental Protection Agency within the first 180 days of operation. Thereafter, if the treatment unit has received general approval, a grab sample is required once every five years. Samples shall be analyzed for BOD₅ and, if disinfection is required, fecal coliform. Treatment units utilizing chlorine disinfection may alternatively sample for TRC instead of fecal coliform. Sample results shall be submitted to the local health department by the 15th of the month following the month in which the sample was taken.

E. For small AOSSs that utilize a treatment unit that has not received general approval, in addition to the initial sample required by subsection D of this section, four additional grab samples of the effluent from the treatment unit shall be collected, analyzed, and submitted to the department within the first two years of operation and annually thereafter. The interval for collecting the samples shall not be less than quarterly or more than semiannually. Sample results shall be submitted to the local health department by the 15th of the month following the month in which the sample was taken. After two years of sampling in accordance with this subsection, the owner may submit a request to the department to reduce the sampling frequency to once every five years. The department shall grant such requests if the mean of five or more consecutive samples complies with the applicable performance requirements of this chapter.

F. Sampling and monitoring requirements for AOSS treatment systems with flows greater than 1,000 gpd are contained in Table 4: