(Written by Jack Milarch – NMHBA EVP/CEO – Originally published in the October 2006 Housing Journal)

A Partial Victory on Revisions to the New Septic Tank Regulations

Our Association has been involved with the NM Environment Department over the last two years reviewing the effects of their 2004 septic tank regulations overhaul. When the big changes finally became effective, the Environment Improvement Board who adopted them said they would be willing to continue the review process. During recent meetings with NMED staff we asked them to consider further changes. They were:

  1. Reduce the new larger drain field sizing back to its former area, and
  2. Reduce or eliminate the requirement for a duplicate drain field “replacement area”

Other “tweaks” which were requested by tank installers included specific regulations for elevated (as contrasted to Mound type) systems, and fixing problems with the new inspection port requirements.

Drain Field Sizing

Our current drain field sizing is based upon the 30-year-old national standard of 75 Gallons of septage Per Day (GPD) for each person anticipated to live in the dwelling. Many experts believe this is too high for New Mexico, especially with the water conservation measures built into modern appliances and plumbing fixtures. In addition we know New Mexico’s dry climate promotes evaporation of a significant percentage of the waste water. While the industry feels common sense is on their side of the argument, there is a lack of state-specific scientific studies to show the actual numbers to prove our case. After much discussion, our only success was that NMED staff agreed “someone” should conduct a study in New Mexico to determine the correct GPD requirement, but in the meantime the old national standard will stay. We will ask the Waste Water TAC to look at this issue and report back to you.

Replacement Drain Field Area

NMED agreed to support reduction in the size of a replacement area for drain fields to 50% of the size of the original drain field. While this is not a complete elimination we had hoped for, it is a significant reduction. The current requirement often causes problems on steeply sloped and difficult lots.

Elevated Systems

Elevated septic tank systems regulations have been lumped into the Mound Systems section, where they did not really fit. Las Cruces member Bobbie Suggs suggested better wording which NMED has accepted and incorporated into their planned revisions.

Inspection Ports

Inspection ports were required to be above-ground in the 2004 revisions. As we predicted, this is causing problems because construction activity on the lots is taking these ports out of commission even before the homeowners have moved in. NMED has been hearing complaints from the field and has agreed to allow the inspection ports to be underground, probably in landscape irrigation type “vaults”, in certain circumstances.

While we didn’t get everything we asked for, we did make some significant headway on these issues, and opened discussion on critical issues such as the antiquated 75 GPD standard.

If you have opinions on these changes please let NMED know prior to their January public hearing.