The TMDL Study will be submitted to EPA where they will have 30 days to review and approve the TMDL. Then a TMDL Implementation Plan (TMDL IP) can be developed to bring the impaired water body up to standards. TMDL IPs include a schedule of actions, costs, and monitoring. Plan development, ideally, should start as soon as possible after EPA approval of the TMDL Study. Virginia state law requires the development of a TMDL IP. Either state or local agencies can take the lead in developing TMDL IPs.
DEQ and DCR intend for nonpoint source TMDLs to be implemented through Best Management Practices (BMPs) and expect that implementation will occur in stages. The benefits of staged implementation are:
- As stream monitoring continues to occur, it allows for water quality improvements to be recorded as they are being achieved;
- It provides a measure of quality control, given the uncertainties which exist in any model;
- It provides a mechanism for developing public support;
- It helps to ensure the most cost effective practices are implemented first; and
- It allows for the evaluation of the adequacy of the TMDL in helping meet the water quality standard.
What if it is not feasible to reach Water Quality Standards due to nature or uncontrollable factors?
DEQ's focus in this area is to ensure that water quality goals are appropriate and worth the resources that will need to be expended to achieve them. In some of the streams, fecal coliform bacteria counts contributed by wildlife results in standards violations. In order to address this issue, the Commonwealth has developed a secondary contact recreation use. This new designated use will become effective pending EPA approval. To reclassify a specific stream's designated use, the state must demonstrate that the source of bacterial contamination is natural and uncontrollable by effluent limitations and BMPs through a special study called Use Attainability Analysis (UAA).
Is there a list of Best Management Practices that might be employed in urban areas?
Each TMDL is specifically tailored to address the conditions and circumstances that pertain to that impaired water. Many urban area BMPs used in the past to reduce human bacteria loading from failing septic systems and leaking sewer lines include education on septic pump-outs and a santitary sewer inspection and maintenance program. Also beneficial are controlling urban wash-off from parking lots and roads through ordinance enactment aimed at reducing fecal loads from pets, improved garbage collection and street cleaning.
Is there a list of Best Management Practices that might be employed in agricultural areas?
Again, each TMDL is specifically tailored to address the conditions and circumstances that pertain to that impaired water. Many agricultural BMPs used successfully in the past to lower bacteria levels include livestock fencing from streams, reducing stormwater run-off in barnyards and feedlots by additional buffering in the riparian zone, and manure management practices. In residential areas, addressing failing septic systems and straight pipes have been very effective.
- from Frequently Asked Questions About. . . TMDL Implementation, Virginia Department of Environmental Quality, June 2003, by J. Schneider.
About TMDL IPs