Stricter discharge permits are changing the way utilities across the western U.S. think about wastewater. Increasingly, the question is not just how to treat water before releasing it back to the environment, but whether to discharge at all. In a recent interview with Wastewater Digest, Carollo Senior Project Manager John Rehring discussed how discharge avoidance is emerging as a powerful driver for potable reuse projects and what it means for the future of water management.
Why Discharge Avoidance Matters for Utilities
According to John, discharge avoidance stems from evolving permits that impose tighter limits on conventional parameters, such as nitrogen and phosphorus, while introducing entirely new requirements. “Some of the things we’re starting to see now are limits on temperature or dissolved constituents like chloride and sulfate,” he explained. “Most water resource recovery facilities just aren’t equipped to remove these, and putting the technology in place would be very expensive and operationally complex.”
Instead of investing in costly new treatment processes simply to discharge water, utilities are considering whether it makes more sense to reuse that water as part of their supply portfolio. “What if we were to discharge less of that flow so we didn’t have to treat it with all these new processes, or maybe eliminate discharges altogether?” John said. “Could we instead take that water, purify it, and put it into the drinking water system?”
The Role of Direct Potable Reuse Regulations
The feasibility of potable reuse is also being shaped by new regulatory frameworks. Four states, Colorado, California, Florida, and Arizona, now have direct potable reuse (DPR) regulations in place. For John, that clarity is critical. “Having the regs in place really facilitates fact-based decision-making,” he explained. “If we don’t know the rules, we have to assume conservative requirements, which makes projects look more expensive than they might actually be. With the rules in place, we can plan around them, have real-world costs, and make smart decisions.”
These regulations not only guide utilities but also build public confidence. As John emphasized, “It’s not just, ‘trust us that the water’s good.’ There’s a third party looking over our shoulder to make sure the water’s safe.”
Communicating Potable Reuse to Communities
Community engagement is essential when introducing potable reuse, particularly when driven by regulatory compliance rather than water scarcity. John underscored the importance of transparency: “First and foremost, the most critical thing is open, fact-based communication. We don’t have anything to hide.”
Demonstration facilities, like the one developed with Colorado Springs Utilities, are powerful tools for engagement. “Seeing is believing, but tasting is really believing,” John said. Technical tours coupled with education about local water resources help stakeholders understand the challenges and trade-offs utilities face, creating space for informed community dialogue.
To hear more of John’s insights on discharge avoidance, potable reuse, and the future of water management, watch his full Wastewater Digest interview below:
