The
Chesapeake Ranch Estates (CRE), where I live in Lusby, Maryland is a good place to promote humanure composting. Every one of our 4,000+ unique single-family dwellings is connected to a septic tank. About one-tenth of our residences are in the critical area, magnifying, manyfold, their potential for polluting the Bay. The EPA standard for septic system density is at 40 systems per square mile, an area's groundwater is most likely being overly contaminated. CRE's septic system density is around 900 systems per square mile.
Calvert County's phase II Watershed Implementation Plan (WIP) to help reduce pollution of the Chesapeake Bay watershed is relying on a few demanding measures to improve the nitrogen removing performance of septic systems. By installing denitrifying septic systems, they can eliminate up to 93% of nitrogen discharge to the watershed from those sites. The government's cost to execute the WIP will require double the current budget, but a lot of the cost will be borne by homeowners who would have to install the improved systems at costs up to $12,000. Failed septic systems, new systems, and existing systems belonging to homes being sold would all require the expensive new technology. The WIP says nothing to encourage alternatives such as composting toilets.
The Maryland Department of the Environment makes the composting toilet alternative only mildly attractive by allowing a dwelling's septic system to be sized about 1/3 smaller. The regulations only address waterless toilets in the context of waste
disposal. In particular, they address “On-site disposal” which they define as "the disposal of sewage effluent beneath the land surface." They also levy additional
permitting and inspection requirements on owners of waterless toilet systems that dispose of the sewage on-site. The whole process would appear to drive the on-site disposal alternative into the loss bracket for most homeowners.
The regulations do not delve into the possibility of recycling the manure through thermogenic
composting in bins
above the ground. With that approach, once it is fully composted and cured, the material is no longer "sewage" and applying it to gardens can't be properly described as "disposal." The absence of regulation on this topic leaves it up to the citizenry as to whether they recycle their excreta, though there may also be local rules to deal with. My guess is that the county would jump at the opportunity to take nitrogen credit for hundreds of households that have stopped flushing toilets into their septic tanks and, instead, make water purifying compost out of humanure.
