The St. Mary's County Board of County Commissioners has issued a letter to Governor Martin O'Malley calling on the state to rethink its implementation of new septics regulations.By googling around, I think I found what the 30%, 50% and 80% refers to:
Commissioners say serious questions have arisen with regard to the Best Available Technology (BAT) septic systems which will be required throughout the Chesapeake Bay and Atlantic Coastal watersheds in Maryland. While in general support of the goals of nutrient reduction and water quality improvements, the board remains "strongly opposed to the implementation of these regulations without addressing apparent flaws to the practicality and implementation of such a far reaching set of regulations."
The new Maryland Department of the Environment nitrogen delivery system scheme of 30%, 50% and 80% replaces the current 40% delivery rate used by all other states. Commissioners say the three tier delivery system would cost the county an additional $45 million to implement. The board is also "deeply troubled by inconsistent methodologies that yield unbalanced and unworkable impacts at the local level."
Commissioners say they hope the Governor would "slow down the implementation process, further evaluate the data and initiate further discussions with local government."
• 80% for septic systems within the Critical Area (1,000 feet from tidal surface water)The percent refers to how much of the nitrogen from a septic system is presumed to reach the bay. For very close systems (Critical area), most of the nitrogen (80%) is presumed to reach the Bay and progressively less for more distant systems. In a place like St. Mary's county, with water on two sides, and many residents seeking water front, this could produce a greater weighting than, say in upstate New York at 40%, and require St. Mary's to achieve higher levels of reduction. Fair? Maybe, but the arbitrary even numbers for the attenuation rate suggests they were pulled out of someone's ass.
• 50% for septic systems outside the Critical Area and within 1,000 feet of nontidal waters
• 30% for all other septic systems