First, I would like to express my agreement with the comments posted by Jason Churchill and Kevin Sherman.

It is clear from some of the comments currently posted that there is some confusion about the permitting of AOSS in Virginia in general and the permitting of engineer designed AOSS under H.B. 1166 (GMP #146). The vast majority of AOSS permitted in the Chesapeake Bay Watershed and throughout Virginia are done so on properties that would not be classified as “wetlands” and that utilize 6” to 12” or greater of natural well-drained soils above the seasonal water table. I have no issue with making nitrogen reduction technology mandatory and requiring TL-3 effluent as part of an engineered AOSS permitted under GMP #146. I do have issue with making nitrogen reduction mandatory for properties where the site and soil conditions comply with the requirements of the Virginia Sewage Handling & Disposal Regulations for alternative treatment and are acceptable under the current Emergency Regulations for TL-2 effluent.

If Virginia is set on establishing nitrogen reduction standards then I would suggest that a more comprehensive and targeted scientific approach be considered that addresses all small onsite sewage systems (septic tank effluent as well as AOSS) within defined critical areas inside the Chesapeake Bay Watershed. The simple fact is that unless ALL onsite systems within critical areas are considered, we are only paying lip service to the problem as conventional septic tank effluent sewage systems far outnumber small AOSS within the Watershed and many of the more “at risk” systems are conventional septic systems installed under previous, less restrictive regulations. I realize that these proposed regulations deal specifically with AOSS and that additional regulations will be required in order to address septic tank effluent systems. I would like to propose VDH consider the following revisions to 12 VAC5-613-90-D:

1. Establish a “critical area” defined as all area within 300 feet (100 yards) measured vertically from the high tide mark of the Chesapeake Bay and from the water's edge of rivers and tributaries within the Commonwealth. All small AOSS located within the critical area would be required to incorporate nitrogen reduction technology capable of reducing total nitrogen (TN) by 50% (20 mg/l or less).

2. The use of nitrate loading calculations and dilution rates to try and justify nitrogen reduction shall not be allowed when designing small AOSS within the critical area.

3. VDH to establish a field testing program modeled after the testing protocols in GMP #147 to allow AOSS nitrogen reduction manufacturers to validate their reduction claims by requiring 4 quarters of testing on 20 single-family residential systems. These systems would need to meet a nitrogen reduction standard of 20 mg/l or less.

VDH should then pursue through the Legislature additional legislation that will require conventional septic tank effluent systems located within the critical area to also incorporate nitrogen reduction technology. Existing septic systems within the critical area would be required to upgrade to nitrogen reduction systems once their existing systems fail and need replacement. Existing systems within the critical area would not be eligible for a waiver from the nitrogen reduction requirement. Finally, as an incentive, a one-time “green” state income tax credit could be offered to property owners who install a nitrogen reduction system whether within or outside of the critical area.

Only if these sequence of steps are taken, would the state have any real impact on reducing nitrogen from onsite sewage systems in relation to the Bay.  However, since onsite septic systems only account for about 4% of nitrogen entering the Bay (Chesapeake Bay Program Phase 4.3 Model 2007 Simulation), the larger agricultural, atmospheric, municipal and industrial sources will need to be addressed before any significant nitrogen reduction in the Chesapeake Bay can take affect.