Mojave desert utility to build twin MBR plants

Two identical membrane bioreactor plants are being planned by the Victor Valley Water Reclamation Authority (VVWRA) on the edge of the Mojave desert east of Los Angeles, USA.

Having recently been given necessary permits, approval by VVWRA’s own commission is the last step for the projects at the Hesperia and Apple Valley water reclamation plants. Once that happens, the agency is ready to release a bid to construct the projects, which have been in planning for two decades.

VVWRA’s Ryan Orr told D&WR that both plants would have an initial capacity of 1 MGD (3,785 m³/d) rising to 4 MGD (15,140 m³/d).

“It should be noted that due to the conservation efforts and geography in our area, the local water contractor estimates that two households live off of one acre foot (1,234 m³) per year,” Orr points out. “Although the plants will only be producing recycled water for secondary uses — primarily irrigation — I find it useful to illustrate the offset in potable use.”

The water supply in the High Desert is primarily groundwater, which is currently overdrafted. The Mojave Water Agency (MWA) has an entitlement to State Water Project water, but has historically not taken its full entitlement.

A stipulated judgment (January 1996) requires the agency to provide “makeup water” to achieve a water balance between its subareas. Water reclamation will help to reduce the burden upon the groundwater supply and State Water Project by increasing the efficiency at which the groundwater is used by offsetting some non-potable water demands.

Recycled water also tends to be less expensive than potable water and, as such, provides an economic benefit to the end-user. The MWA has identified water recycling by VVWRA as a significant management tool in its water management plan.