Mind the brine in reuse planning: Mass-balance modeling in reuse planning enables utilities to balance costs and benefits

The benefits are more obvious than the costs. Where water is scarce, utilities understand the importance of reuse to augment water supply, and the public is generally on board with the concept. Dwindling high-quality water supplies, water treatment facilities reaching their design capacities, and the steep cost of expanding water production are significant drivers for wastewater reclamation.

Communities in the initial stages of reuse planning are in an especially good position to decide how much reuse-water they can sell to industrial customers before the costs outweigh the benefits. They can identify the optimal mix of reuse customers, determine how much water to reclaim and sell to those customers, and establish prices knowing that a certain level of reuse sales to certain...

Utilities that choose to enlarge reuse programs or that are already past the point at which TDS removal and brine management become necessary have many options.

Years ago, a utility in the midwestern U.S. was approached by two power companies and an industrial customer that wanted to build facilities in the metro area. One power company wanted to buy reclaimed water from two sources — one of the utility’s smaller WRRFs and a nearby WRRF owned by another utility — and discharge water to the utility’s largest...

Reuse offers many benefits for communities. But planning for reuse is the key to managing both income from water sales and expenses for investment. Exceeding thresholds for volume-of-water-sold can necessitate investment in TDS removal and brine management. While this improves product quality, it significantly increases the cost of reuse-water production.