(Originally published in the December 2007 Housing Journal)

Update on Alternative Treatment Units for Liquid Waste Disposal

Biggest problem is failure to comply with monitoring requirements

Builders who have had Alternative Treatment Units (ATUs) installed may be hearing from some of their former clients when the home owners get letters from the New Mexico Environment Department (NMED) soon. There are several problems: 1) many ATU owners are not having their effluent sampled and reports sent to NMED; 2) several ATU manufacturers are not fulfilling their maintenance contract obligations, even when the homeowner is willing to pay for it; and 3) in a few cases the ATUs cannot produce effluent that complies with the permitted limitation.

ATUs are largely installed in areas where soil conditions won’t allow the percolation needed for proper drain field treatment of liquid waste effluent. Because the Ruidoso area has so much rock, ATUs have become more the “norm” than the “alternate”. NMED prepared a report last December to analyze the problem, and transferred a full-time staff person into the Liquid Waste Program just to deal with writing letters and processing the estimated 300+ Compliance Orders to try to get voluntary compliance. Quarterly meetings with installers and maintenance providers in the Ruidoso & Portales areas have been held to train the industry on proper sampling and testing techniques. Compliance in those areas has nearly doubled, to 60%.

From 1997-2006, 627 ATUs have been permitted and installed with effluent limitations and monitoring requirements. Each ATU is required to have quarterly sampling of its effluent, with the requirement tapering off if the system passes, and additional treatment/sampling being required if the ATU is not performing properly. Of the 627 ATUs required to report, no effluent test reports had been submitted for 382 (61%) of the systems; 1-5 reports have been submitted for 234 (37%); six or more reports have been submitted for 11 (2%) ATUs. NMED sent letters to the owners of these systems so they could begin to get their maintenance providers to comply with state requirements. Compliance numbers have improved a little this year but 36% of these systems still have no samples submitted, according to this month’s report from NMED.

Several ATU manufacturers have gone out of business, and the owners of these systems are left with “orphans” that required the homeowners to search for a maintenance provider who would agree to take on the contract for their ATU. Several out-of-state manufacturers who are still in business flatly refused to offer maintenance contracts for the few ATUs installed in New Mexico, and NMED is in the process of decertifying these systems so other homeowners do not install more “orphans”. In other cases the ATU simply cannot be made to work properly because the system was a bad design.


More ATUs Required in September 2008

Add to this the fact the Liquid Waste Disposal Regulations that went into effect September 1, 2005, allowed three years’ “grandfathering” of half-acre lots with domestic water wells to continue to install conventional septic systems until September 1, 2008. This “grandfathering” comes to an end next September and will require ATUs on thousands of half-acre lots from Moriarty and Rio Rancho all the way down to Silver City. September 2010 will see an end to “grandfathering” on half-acre lots even with municipal water, and many thousands more lots will be required to install ATUs. The NMED Wastewater Technical Advisory Committee was told this month there is a 50% failure rate among ATUs nationwide.

NMED is working feverishly to attempt to get the existing 627 ATUs into compliance, and work out the problems with the “orphaned” systems before the problems explode into cataclysmic proportions starting next September. Solutions for the technical issues were discussed with the NMED Wastewater TAC, but ultimately the administrative solutions for tracking ATUs and issuing Compliance Orders rest with NMED staff. NMHBA has offered any assistance NMED might need to help the process along so our members can continue to build on half-acre lots across the state.