Unlocking Sustainable Water Management
Engineer Erin English calls for the removal of the roadblocks that impede progress in implementing integrated water strategies.
Urbanization and agriculture have, in many regions, placed unprecedented stress on water availability and quality. Many regions import water from beyond their own watershed boundaries, often expending great capital and energy expense to transport, treat and discharge water. Although many centralized, municipal-scale systems are efficient due to economies of scale, the ongoing cost to maintain and upgrade this massive infrastructure in the face of climate change will become even more daunting and expensive. Despite all the associated expenses, when it comes down to it, the cost that most people pay for water is still fantastically low. Water conservation – as well as investment in newer, flexible systems aimed at improving water sustainability – doesn’t always appear to make economic sense, at least on the surface. Water reuse, decentralized infrastructure, and water efficiency are powerful – and ultimately affordable – tools that have not yet been used effectively across a broad range of conditions.
Decentralized water systems that offer built-in redundancy, such as neighborhood or district scale wastewater treatment and reuse can add resiliency to and complement our current centralized infrastructure. An effective model for decentralized water would provide for proactive, flexible and sensible water reuse, and encourage recharge of the groundwater. Passive, low-energy systems based upon ecological processes may reduce both the cost and carbon intensity of water infrastructure, while providing other stacked benefits such as open space, habitat and beauty. Aggressive water reuse, water harvesting and water efficiency measures can help communities adapt to changing water availability while reaching toward ‘net zero’ or perhaps even ‘net positive’ water projects. These aspirational goals of net zero and net positive envision buildings that produce more clean water than they use by recycling, filtering and slowly re-releasing this precious resource into the surroundings.
However, a number of regulatory barriers have impeded efforts to implement these types of projects. It is very difficult and expensive to permit some methods of enhancing water efficiency. For example, county-level public health codes currently prohibit or limit the use of clean, filtered rainwater for non-potable reuse and drinking. There are three overarching areas that need reform to maximize the efficient use and reuse of water in decentralized systems. Resolving these regulatory road blocks would improve water management and reduce water shortages and waste, without compromising the public health they are designed to protect.
- Greywater Reuse. It should be easier to reuse greywater to support landscaping and meet non-potable demands in buildings (e.g. to flush toilets with water from sinks). Permits should be more freely available to not only residential users but also to commercial and institutional facilities. This is usually controlled on a state-by-state basis or at the county level. Some states outlaw greywater reuse altogether, or require a ‘full’ discharge permit, which is expensive and complicated. There are some sensible approaches already on the books that streamline permitting, treatment and testing requirements (e.g. Arizona, New Mexico), and these should be used as case studies to guide best practices.
- Potable Water Production. Clean and filtered rainwater should be available for residential and commercial/public use for both potable and non potable purposes. Counties need to develop a variance process to make exceptions and allowances for best practices in water reuse. The federal government could help urge allowances for such procedures in the Universal Plumbing Code and other guidelines.
- Remove barriers to using reclaimed wastewater. Policies governing reclaimed wastewater treatment and use do not respond to scale. Small, decentralized systems should not be held to the exact same standards as municipalities. For example, at the municipal scale, daily testing of fecal coliform is warranted but this standard is prohibitive for smaller systems, especially where the reuse approach limits exposure and risk.
Author David Sedlak, whose book Water 4.0 examines the way civilizations have managed water for the past 2500 years, believes decentralization will be a key part of the next revolution in water management. I agree. I also agree that the time for this revolution is now. Let’s begin by removing our barriers to progress.
By Erin English
We face an urgent need to use our water more sensibly and conservatively, but some of the best solutions are difficult to implement in the current regulatory and economic framework.