As part of its ongoing collaboration with the DigDeep Navajo Water Project, the International Water, Sanitation and Hygiene Foundation (IWSH) recently designed and installed two pressurised mound septic systems in the Baca-Prewitt area of the Navajo Nation, about 40 miles east of Gallup, New Mexico.

Work begins. Image supplied by IWSH

Work begins. Image supplied by IWSH

These two sites will now serve as a demonstration for Navajo Nation authorities and members of the community so that they can see how engineered systems could be selected, designed and utilised on the reservation. The community is now also able to learn about the functionality, maintenance and appearance of pressurised systems.

Navajo Nation is the largest land area held by a Native-American tribe in the U.S. More than 30 percent still do not have a tap or toilet at home – Navajo are 67 times more likely than other Americans to live without running water or a toilet.

The Indian Health Service (IHS) has committed to funding pump trucks for certain Navajo communities and septic tank disposal facilities, but there is a great need to repair or replace failed conventional septic systems.

Knowing that soil conditions dictate the type of septic system that would be suitable for the area, IWSH contracted with Sam Woolsey of Woolsey Plumbing in Waupaca, Wisconsin: a licenced soil tester who is also a member of Plumbers & Steamfitters UA Local 400 in Kaukauna, Wisconsin.

Woolsey assessed the soil at several homes in the Baca community, and then with DigDeep’s guidance, designed two septic system plans for a four and five-bedroom home. Infiltrator Water Technologies, through its distributors at Dahl Plumbing, in Albuquerque, New Mexico, donated the septic tanks and the EZflow synthetic aggregate, which is used to filter the effluent in the drain field.

These components, coupled with the exterior plumbing materials purchased from Winsupply of Albuquerque – a long-standing supporter of IWSH’s community plumbing efforts on the Navajo Nation – and the specific washed sand purchased locally, enable the mound systems to treat wastewater from the home.

This helps eliminate the leach line ponding that has become a common occurrence for homes in the Baca area.

Learn more about the DigDeep Navajo Water Project at