Thoughts From Engineers: Water Reuse Enters the Spotlight
The Wichita Falls Resource Recovery Facility in Wichita Falls, Texas, became a national model for indirect potable reuse (IPR) in 2018 when it captured, disinfected, filtered and oxygenated wastewater before delivering roughly 20 million gallons a day to the city’s drinking water reservoir, Lake Arrowhead. A prime example of making the most of a city’s water supply, the city now treats and reuses what would have been discharged as effluent 10 years ago.
Pure Water San Diego is in the process of implementing a larger sewage-recycling system that will, when fully operational in 2045, make up half of San Diego’s water supply by treating nearly 83 million gallons a day.
The underlying concept here isn’t new: water has long been collected and reused for other purposes. What’s steadily changing, however, is the degree to which states, industry and others are experimenting with use of graywater and wastewater to either purify as a source of public drinking water or to recycle for a suitable, non-potable use. To the extent a community—or singular building in some instances—can capture and repurpose a source of water for secondary use, stakeholders gain on multiple levels. Water, used once and disposed of just as readily, now cycles through yet again.
This trend is gaining momentum for multiple reasons, but one reality looms large: freshwater is limited to begin with, but capturing it for reuse makes a city much more resilient and water secure in the event of drought or other unforeseen circumstances.
Returns on Reuse
The rate at which states have been funding reuse projects through the U.S. Environmental Protection Agency (EPA) Clean Water State Revolving Fund has been steadily increasing through the years. Since its beginning in 1988, the program has distributed more than $1.9 billion in financial support for reuse projects. Most of these projects are in specific areas of the United States, with California, Florida and Texas at the forefront of the larger-scale initiatives. Increasingly, however, historically water-secure states and municipalities—through public/private partnerships—are designing ways to creatively fortify their water reserves while reaping other benefits.
These initiatives take a variety of forms with a mix of private and public entities poised to benefit. For example, in water-rich Virginia, treatment facilities run by the Hampton Roads Sanitation District treat wastewater drawn from a multiple-county service area to a high degree of purification, at which point the water is reinjected into the Potomac Aquifer, a groundwater source that has been depleted due to high withdrawal rates by industry. The operation, also known as the Sustainable Water Initiative for Tomorrow project, serves multiple purposes by replenishing the aquifer, preventing seawater intrusion and land subsidence, and enhancing water quality in nearby surface waters by reducing effluent discharges to Chesapeake Bay.
Paper manufacturer Green Bay Packaging in Green Bay, Wis., entered a partnership with NEW Water, Green Bay’s advanced wastewater treatment facility, to use NEW Water’s recycled water for its manufacturing processes. Tampa Electric represents another example of industry in a beneficial partnership with the public sector as it draws on recycled water from neighboring municipalities to cool power stations.
Projects such as these will increase in number if the support—financial, institutional and regulatory—is there. The U.S. EPA stepped up in 2018, launching the National Water Reuse Action Plan (WRAP) collaboration with partners across the water industry. This initiative, which brings in nearly 100 federal and local agencies, organizations and others to create a support system for future water reuse projects, marks a shift in the national mindset.
In the words of WRAP’s website, the effort “was developed with federal, state, tribal, local and water sector partners to build technical, financial and institutional capacity for communities to pursue water reuse practices.” The WRAP initiative represents a move away from traditional, piecemeal water management to one that considers how water systems can be managed for efficiencies of design, scale, cost, growth and the health of the watershed as a whole.
Developing Workable Standards for Water Reuse
A status update on WRAP program initiatives was released in April 2021 with progress noted in the financial, institutional and research sectors. For example, guidance and training materials on the establishment of onsite non-potable water systems have been developed. This material brings together public-health standards and current regulations to offer workable guidance for new reuse projects.
Work is in progress to develop “fit-for-purpose specifications” for recycled water. The potential to implement stormwater capture technology on a larger scale also is being explored. This methodology is being used by General Motors at its Factory ZERO plant in Detroit, where collected stormwater is used for cooling purposes and during the automobile manufacturing process.
In terms of providing financial support, numerous grant programs, including the Clean Water Act and Drinking Water State Revolving Fund clarified eligibility for reuse projects. The Water Infrastructure Finance and Innovation Act provided more than $1 billion in support of local water reuse projects. Recent financial support also includes $27.5 million awarded by the U.S. Department of Energy for projects that research the development of water recovery and reuse technology systems.
A Paradigm Shift in How We Manage Water
Although Wisconsin—my home state—has seen its share of extreme rain events in recent years, the state is technically in a drought this summer. Water utilities in Madison—where I live—considered water-use restrictions in early June 2021. The bottom line is that neither rain nor a risk-free water supply is a certainty these days, no matter where you live. Plentiful lakes and rivers throughout much of the United States—together with an easily replicated formula to move, distribute and dispose of water in communities across the country—meant our historic approach to water management has long reflected a mindset of plenty, with more to spare.
We’re at a crossroads in terms of rebuilding the country’s water infrastructure, and it’s anyone’s guess as to how, under what time frame, and at what cost this massive undertaking moves forward. As a professional civil engineer, I appreciate the many complexities and challenges specific to each building project. Client interests, costs, site and logistical constraints all factor in the mix and drive the focus, design and ultimate outcome of a project. But engineers are quick to rise to a challenge. During these times, we would be amiss to ignore the hidden opportunity represented by water reuse.