Water Reuse Recycling Systems
By Sharon Steiner
By 2030, 47 percent of the world’s population will live in areas of high water stress (Food and Agriculture Organization, 2007) and water scarcity, and some arid or semi-arid regions will displace between 24 and 700 million people (UNCCD). It’s important to note that while this may not be happening today, it is imminent and requires the attention of our communities.
Several factors are contributing to these water crises, including deforestation, pollution, overgrazing and urbanization, as well as inefficient irrigation and wastewater treatment practices. Studies show that up to 70 percent of the world’s aquifers have reached peak water demand and nearly 50 countries are officially classified as being water stressed (Global Water Institute, 2013). Changing weather patterns have led to prolonged droughts in some regions and increased flooding in others. Lower temperatures are affecting glaciers and snow packs, which in turn impact freshwater supply and availability.
Additionally, freshwater from the world’s underground aquifers is being extracted at unsustainable rates. Population growth coupled with rising global incomes puts pressure on increasingly scarce water supplies and crumbling infrastructure. Waste due to leaks and inefficient or outdated facilities is a major factor, with an estimated six billion gallons (22 billion liters) of treated water lost per day from leaky pipes in the US. Lastly, water is extremely undervalued globally; the price of acquiring water is cheaper than implementing water-saving technology.
While we have not yet reached that sobering statistic cited earlier, there are already many densely populated areas across the globe that have major water shortages, including:
- India, which is undergoing the worst water crisis in its history. Some 600 million people face high to extreme water stress; 75 percent of households do not have drinking water at home and 84 percent of rural households do not have piped-water access. About 70 percent of India’s water is extremely contaminated and it is currently ranked 120 out of 122 countries in the water quality index. Several major cities (including New Delhi, Bengaluru, Chennai and Hyderabad) will run out of groundwater this year, affecting 100 million people in India. Additionally, assuming the same business as usual practices, six percent of the country’s GDP (gross domestic product) will be lost by 2050 due to the water crisis.
- Sao Paulo, where more than 21.7 million people had less than 20 days of water in 2015 when the main reservoir fell below four-percent capacity.
- Beijing is home to about 1.5 percent of China’s population, but has only seven percent of the world’s fresh water. Further, 40 percent of its surface water is too polluted for agricultural or industrial use.
- One in five citizens in Mexico City get just a few hours of water from their taps a week and another 20 percent have running water for just part of the day. The city imports as much as 40 percent of its water from distant sources but has no large-scale operation for recycling wastewater (BBC News).
While implementing water-saving technologies is likely the only way to truly address the crisis, there is a legitimate concern with drinking recycled water, as it is critical that pathogens and contaminants are removed appropriately. NSF International partners with industry experts to create standards that protect public health. It also takes opportunities to create standards that promote new technology that will give the public safe access to life-sustaining elements such as water.
In response to the looming crisis, the water reuse standard, NSF/ANSI 350 for Onsite Residential and Commercial Water Reuse Treatment Systems, was created in 2011 to empower manufacturers to develop systems using water-saving technology. The standard’s performance requirements provide citizens and governments with assurance that the onsite greywater being used is safe for its intended use of subsurface irrigation and toilet flushing. It has residential and commercial categories for systems that may treat residential laundry, bathing, combined black and greywater, and commercial greywater.
As direct human ingestion of treated greywater is unlikely, a properly maintained system carries little risk of public health hazards. Systems certified to NSF/ANSI 350 undergo a 26-week test, demonstrating the rigor of the technology, as the systems must achieve effluent with an overall test average of less than 10mg/L for CBOD5 (carbonaceous biochemical oxygen demand), 10 mg/L for TSS, 5 NTU for turbidity and less than 14 MPN (most probable number )/100ml for E. coli.
Commercial systems must achieve effluent an overall test average of less than 10mg/L for CBOD5, 10 mg/L for TSS, 2 NTU for turbidity and less than 2.2 MPN/100mL for E. coli. These requirements, coupled with the intended final use of effluent for subsurface irrigation and toilet flushing, are intended to safeguard public health and minimize contamination risks. NSF/ANSI 350-certified systems can also earn credits during LEED certification. Onsite water reuse systems also have other positive benefits, such as reduced greenhouse gas (GHG) emissions and reduced water needs.
Standards like this allow NSF to make true progress because it has worked collaboratively and proactively to create innovative yet safe ways to solve a critical problem that plagues millions. When utilizing systems with proven technologies, such as those certified under NSF/ANSI 350, public health risks remain minimal, while improving citizen potable water use rates along with reducing energy use and emissions. Greywater reuse can contribute to water-source stability by reducing demand for potable water for nonpotable purposes. As water scarcity and drought conditions persist globally, onsite greywater reuse creates the opportunity to reduce human impact on our natural environment and can negate some impacts on the ability to acquire safe, drinkable water.
About the author
Sharon Steiner currently serves as the Business Unit Manager for NSF’s Wastewater Certification Program. In her role, she oversees the certification process for all the NSF-listed onsite wastewater manufactures. Steiner works with manufacturers throughout the entire certification process, as well as assisting the onsite wastewater regulatory agencies on local rules and policies. She is also very involved in writing new policy, regulations and standards for the onsite wastewater industry. Steiner has been with NSF since 2002, initially working in the Water Distribution Systems Program, where she served as a senior project manager. Prior to joining NSF, she worked at several analytical laboratories as a project manager and a project chemist. Steiner has a Bachelor of Science Degree from Eastern Michigan University.