I echo the comment #14996 submitted by Peter M. Brooks.  Prohibiting dilution is ignoring the real world benefit of what occurs naturally.  By ignoring this reality the regulations drive up the cost to develop community systems such as the County-owned systems that exist and operated properly in Charles City County and Caroline County.  Those systems serve low and moderate-income households that had a long history of failing septics due to bad soils and high water table but the homeowners could not afford individual alternative systems.  These County-owned and operated systems were developed successfully at an affordable customer cost.  The prohibition of dilution will necessitate an over-designed and hence more expensive treatment system making it unaffordable for low and moderate-income communities.  The ultimate result is that the existing poor performing conventional septic systems will not be upgraded and a solvable public health and environmental problem will not be solved.