RD621 - Evaluation of the Need for 180-day Biochemical Oxygen Demand Sampling – December 21, 2017
SB 1577 of the 2017 General Assembly session required the Department of Health to evaluate the need for 180-day BOD5 sampling for any small AOSS dispersing residential strength effluent and serving no more than three single family residences (attached or detached). A small AOSS has a combined average flow of 1,000 gallons per day or less.
For a generally approved AOSS, the AOSS Regulations, at 12VAC5-613-100.D, require BOD5 sampling within 180 days of system start-up using methods approved by the EPA.(*1) Thereafter, a grab sample is required once every five years. For a non-generally approved AOSS, the AOSS Regulations, at 12VAC5-613-100.E, require BOD5 sampling using methods approved by the EPA within 180 days of system start-up, four times within the first two years of system operation, and annually thereafter.(*2)
Sample results for all AOSS must be submitted to the LHD by the 15th of the month following the month in which the sample was taken. In addition to the sampling requirement, a small AOSS must be inspected annually and its function reported to the LHD using an electronic web-based program. VDH does not normally collect samples through complaint investigations and at this time does not perform random inspections on AOSS. Instead, VDH relies on yearly reports with sampling data from the private sector to assess and monitor performance of treatment technologies used in the marketplace.
AOSS typically utilize a treatment device that resembles a scaled-down municipal treatment plant to produce an effluent that is “cleaner" than septic tank effluent with respect to the amount of organic material, the total nitrogen load, and the number of microorganisms present in the effluent. Typically, AOSS remove 90% to 95% of contaminants before the effluent is released into the soil. Using technology to treat wastewater before it is released into the soil allows AOSS to achieve high performance levels on sites where limiting factors, such as insufficient drainfield area, soil depth and soil permeability; soil saturation; shallow groundwater; or landscape position preclude the use of COSS. There are over 20,000 AOSS in the Commonwealth. The Board of Health adopted the AOSS Regulations in 2011 to establish performance requirements for AOSS.
During consideration of SB1577 and subsequent stakeholder conversations, VDH understands there are at least six concerns regarding sampling for BOD5.
1. Some stakeholders believe the sampling requirements are unnecessary and expensive. DPB assessed the costs for sampling during the regulatory adoption process for the AOSS Regulations and determined those costs were acceptable. For a BOD5 sample collected during a routine visit, VDH estimates it will cost $100.00 to $150.00 (an estimated $35 to $45 of lab costs and the remaining cost attributable to collection and delivery of the sample to a certified lab). The licensed operator is already onsite to operate the AOSS and provide the annual report on the system’s function so costs for collecting the sample and delivering to the nearest lab is minimal in comparison to other costs.
2. Aside from cost, some stakeholders reported that a licensed operator would not need to collect a sample for lab testing and could instead visually inspect and smell the sample for evaluation of system performance and operation. Stakeholders asserted that using visual and smell field testing could substitute for BOD5 sampling.
VDH’s data show that operators cannot discern whether a treatment unit is meeting the performance requirements based on sight and smell. There were approximately 6,450 AOSSs installed from July 7, 2011, to the present. VDH has received about 1,885 O&M reports with sampling data. Of the 1,885 samples, 21% of the data (392 samples) showed high BOD5 results (greater than 30 mg/l) even though operators reported 90% of the time (354 out of 392) that the AOSS was working properly. Some stakeholders believe that high percentages of non-compliance can be addressed with more robust oversight and follow-up with property owners by VDH.
3. Some stakeholders express concern that access to sampling data could only be obtained from requests pursuant to the FOIA with an associated charge.
Beginning December 1, 2017, VDH will start posting data online quarterly. This effort will remove the need for stakeholders to request sampling data and O&M data through FOIA.
4. Some stakeholders believe VDH does not use data from the sampling required by the AOSS Regulations; hence, sampling is unnecessary.
As described in #2 above, VDH has used the data submitted to determine whether VDH and stakeholders can have confidence in a visual and smell test based on sampling data. VDH believes sampling results will help VDH with future regulatory initiatives to improve policy through data driven decisions.
5. Some stakeholders question the initial sample collection within 180 days of system start-up, as the licensed operator could take the sample immediately after startup, before the treatment process has been properly established. Stakeholders believed this results in meaningless data.
VDH is addressing these concerns through a regulatory update of the AOSS Regulations.
6. Many stakeholders agree VDH must improve its programmatic oversight and enforcement and contend that this would result in more relevant data that could be used for the public’s benefit. Stakeholders observe that poor sampling results could result from many different factors, including: (a) improper installation; (b) abuse of the system by the property owner; (c) improper collection procedures; (d) mechanical failure of a treatment process, such as a blower; or (e) improper design.
VDH is addressing these concerns through a regulatory update of the AOSS Regulations.
VDH uses BOD5 sampling data to improve its program and to ensure that AOSSs are complying with performance regulations. Many other states, including neighboring North Carolina and Maryland, also use sampling data to assess and monitor the performance of AOSS. Sampling and reporting facilitates VDH advancement of programmatic oversight and policy improvement, and confirms regulatory compliance. Conservatively, installation and design costs for an AOSS range from $10,000 to $25,000 so the O&M costs are relatively minor to protect that investment.
Stakeholders want performance regulations, not prescriptive requirements, and sampling is the best means to verify performance. If sampling were prohibited, the Board of Health would likely need to reinstate more prescriptive regulations to ensure public health is adequately protected because the industry standard is to collect samples to verify performance of advanced wastewater treatment systems.
Based on stakeholder comments and concerns, VDH recommends the following actions:
1. Revise 12VAC5-613-100.D and E to improve confidence in the BOD5 sampling result. VDH is currently working with the SHADAC, manufacturers, operators, and other interested stakeholders to revise the AOSS Regulations. A periodic review of the AOSS Regulations concluded in 2016 resulting in many comments from stakeholders, which will be addressed during the regulatory revision process.
2. Post O&M sampling data for every AOSS online. Beginning December 1, 2017, VDH will begin posting O&M information on its website and make it accessible to stakeholders. This will facilitate efforts of owners, operators, and designers to improve the design and function of AOSS, and eliminate the need for stakeholders to request data through FOIA. Placing more information into the public domain will help Virginians make informed decisions about choosing a treatment device. Generally, property owners rely on their private consultants to offer advice and anticipate future O&M costs. Posting data online will improve decision-making and make the performance regulations more effective.
3. Continue to differentiate sampling requirements between proven and tested technology and technology that has not been evaluated by an independent 3rd party. For small AOSS, VDH requires sampling four times within the first two years of system operation and annually thereafter for “non-generally approved" (non-proven) technology, and once every five years for “generally approved" (or 3rd party proven) technology.
4. VDH should update its database - VENIS - to improve data dissemination of sampling results and streamline sampling dissemination to stakeholders. The data currently populated and retained within the VENIS database was evaluated for relevancy to O&M and sampling reporting. Data most useful to stakeholders will be extracted from the overall database on a quarterly basis by VDH beginning December 1, 2017. Data will be posted on the VDH website for access by stakeholders. VDH anticipates significant updates to VENIS by January, 2019. These updates should allow continuous improvement of data quality, increased efficiency of information input, and less redundancy.
VDH shared the draft of this report with stakeholders engaged in the periodic review of the AOSS Regulations. Some stakeholders remain concerned about the grab samples being a poor diagnostic of the performance of an AOSS and the perceived lack of enforcement by the Department. Others advocate for a third party annual field audit of systems. These concerns continue to be debated in the AOSS Periodic Review Workgroup for possible amendment of the AOSS Regulations. (See Appendix C for Workgroup Comments on Draft Report).
(*1) "General approval" means a treatment unit has been evaluated in accordance with the requirements of the AOSS Regulations and approved.