County discusses graywater, composting toilets and vault-and-haul costs; seeks household water-use data for pilot

Coconino County environmental quality specialist Zachary Burf and county staff described alternative on-site sanitation options and a county effort to explore lower-cost systems for the Valley area. Burf said graywater reuse is allowed in Arizona under 13 listed regulations and that the county's primary requirements include keeping graywater on the property, using it only for irrigation of non-edible plants (with limited exceptions for fruit trees), and providing a diversion back into the wastewater system during non-watering months. "Graywater is everything but the kitchen sink in your toilet," Burf said, clarifying that the state treats kitchen-sink waste as blackwater because of pathogen risk. He added that diversion valves are required so graywater can be routed back to the wastewater system when irrigation is not occurring. Composting toilets: Burf said composting toilets can be permitted as an alternate wastewater solution but only specific ADEQ-approved proprietary units are eligible. He said composting systems reduce tank and disposal field sizing (he cited a roughly 40% reduction in tankage and disposal footprint for a three-bedroom house) but that available products are limited and sometimes expensive; he named Sun-Mar Corporation as a manufacturer he has seen in permits. Vault-and-haul: Burf described vault-and-haul (vault tanks that are periodically pumped and hauled) as a last-resort option because long-term pumping costs can be high. Using figures discussed in the presentation, he illustrated how required tank sizing is 10 times the design flow and that frequent pumping can become costly, particularly for properties using hauled water where per-capita water use is lower but pumping frequency remains a driver of cost. Pilot and survey: Burf said Coconino County has received technical assistance through the EPA's Closing America's Wastewater Access Gap program to explore affordable on-site options and that staff are seeking resident input via a short anonymous survey about household water use, washers, and graywater practices to inform system design and a potential pilot. He offered paper copies and a QR-code link for the anonymous survey and distributed business cards for follow-up questions.