A Safe & Cost-Effective Alternative Water Supply for Potable Reuse
The future of sustainable water reuse starts with progressive action today. The City of Altamonte Springs, Florida proactively created pureALTA to address our community’s future water needs and diversify the City’s water portfolio.
pureALTA received a 2018 Market-Changing Water Technology award from the International Water Association in Tokyo, Japan and was the only project honored from the United States. The City also won the 2017 WateReuse Innovative Project of the Year at the nation’s preeminent water reuse conference in Phoenix, Arizona.
Groundwork for pureALTA
People are often surprised that a state like Florida, with an abundance of wetlands, lakes and rivers; which has 1,350 miles of coastline; and receives an annual average rainfall of over 50 inches, can have water shortfalls. But we do. Historically, most of our yearly rainfall is lost to the ocean through past “ditch and drain” practices that were installed to provide flood protection and allow additional development of Florida.
The water-dependent, natural environment that makes Florida such a great state to live in also has high water needs, limiting the supply of fresh water for the increasing potable water supply demands resulting from population growth and for agricultural and industry needs. Even Florida has seen periodic prolonged droughts in the past during which water supply and natural systems experienced added stress.
In Florida, water belongs to the state and is considered property of the public. Water consumers are issued permits by one of five regional water management districts, whose boards are appointed by the governor, throughout Florida for specific allocations of consumptive use withdrawal of water from ground or surface water during the period of that permit.
Several years ago, central Florida instituted a regional body called the Central Florida Water Initiative (CFWI). The CFWI includes on its committees many of the region’s public and private practitioners, and together they discuss future water needs, conservation measures, as well as review the amount of fresh groundwater that has been allocated in those water management district permits and how that consumption could cause harm to the natural environment. The CFWI has determined that the amount of fresh groundwater that has been permitted is not sustainable.
Altamonte Springs as an Environmental Leader
In the 1980s, Altamonte Springs created a project known as Project APRICOT – which stands for “A Prototype Realistic Innovative Community of Today.” We had high aspirations!
Project APRICOT is our dual water and wastewater treatment system that creates our City’s reclaimed water and it was the first of its kind in the southeast United States. Today almost every property in Altamonte Springs is connected to reclaimed water to irrigate lawns and landscaping. Many communities are struggling to fund and install reclaimed water systems. Ours started 33 years ago and is still the model used by planners and engineers.
In another first for Altamonte Springs and the state of Florida, the Florida Department of Transportation (FDOT) agreed to NOT build a retention pond. Instead, the City now captures stormwater from I-4 and treats it to reclaimed water standards. Our system has the capacity to create one billion gallons of alternative water supply for our region that otherwise would have been lost to evaporation or slow percolation.
This project is known as A-FIRST and was the brainchild of City engineers. A-FIRST stands for Altamonte Springs-FDOT Integrated Reuse and Stormwater Treatment and is the first partnership of its kind in Florida. Before A-FIRST, stormwater would run off I-4 and flow into drainage ponds along the side of the road. Over time, the water and some pollutants would seep into the groundwater. Now, stormwater is captured, treated and redirected into the City’s reclaimed water system and used for irrigation.
Why We Created pureALTA
The City of Altamonte Springs is a smart community that has been a national leader in water reuse for nearly 40 years. We are inland, about 12 miles north of Orlando. Although the City’s current water allocations should meet the City’s needs for the next 10 years, the City recognizes the importance of identifying alternative water supplies now in order to be prepared for the potential scenario when additional fresh groundwater is unavailable to meet future needs.
The City implemented pureALTA as a demonstration pilot project to investigate potable reuse as a locally available alternative option to augment the City’s water supply, but we sought also to demonstrate that reuse water could be treated to potable water standards, or better, without reverse osmosis (RO).
Much research has been done on treatment processes that rely on RO as part of a multi-barrier approach to purify treated wastewater for potable reuse. These RO-based treatment trains are well proven; however, they are capital and energy intensive and produce and RO brine that can make it a technically unfeasible alternative for utilities that do not have access to traditional brine disposal options (ocean outfall or deep injection wells) which is the case with most of inland Florida, including Altamonte Springs. The capital and energy requirements of RO make potable reuse unaffordable for most communities on the globe.
Altamonte Springs recognized that if potable reuse is going to be a viable future water supply option, then less energy intensive treatment technologies that do not produce a concentrated brine byproduct would be needed.
What is Potable Reuse?
pureALTA creates purified wastewater for drinking water purposes. The most common technical term is “potable reuse” which is the use of highly treated and purified wastewater that is processed for drinking water.
There are two general kinds of potable reuse―direct and indirect. “Direct potable reuse” is treated water that is delivered directly to the drinking water system. “Indirect potable reuse” is water that is delivered to the environment, such as injected into an aquifer or used to augment a surface water source of drinking water, prior to being later withdrawn for treatment and used in the drinking water system.
With its pureALTA demonstration pilot project, the City of Altamonte Springs is exploring direct potable reuse as a more sustainable alternative that doesn’t require the additional energy intensive steps of indirect potable reuse of pumping the water produced through potable reuse into the aquifer for later withdrawal and costly re-treatment.
pureALTA Goals and Objectives
Altamonte Springs wanted to demonstrate a treatment system that produces purified water that meets or exceeds all drinking water quality standards. This would create an alternative water supply that is protective of public health and uses an energy-efficient technology to reduce or eliminate the production of a brine waste product. We had two primary goals for pureALTA and both are based on people.
First, we created pureALTA because our future residents will one day rely on an alternative water supply. pureALTA will provide our residents with purified drinking water that is better than the water they are drinking today. Second, we created pureALTA for other communities around the world who may not have the resources to create a project like this. We have always believed Altamonte Springs should plan and lead. It’s called that the “Altamonte Way.”
Regulation Trailing Innovation
Florida has started developing a potable reuse regulatory framework. The state has been a leader in environmental protection and a pioneer in the nation for the development of comprehensive reuse regulations in the 1980s and early 1990s addressing public access reuse and indirect potable reuse, but these regulations fall short of addressing direct potable reuse. This year, a group of water treatment stakeholders joined together to form a Potable Reuse Commission to begin developing recommendations for a potable reuse regulatory framework, which will evolve over the next few years as the Florida Legislature starts to wrestle with Florida’s water future. The City of Altamonte Springs will share all of its data and testing results with the Florida Department of Environmental Protection (FDEP) to aid in the future development of a regulatory framework for direct potable reuse.
The greatest challenge is always the least technical, and that is time. The regulatory development process is slower than the growth facing Florida. Consumptive use permits far exceed the water reasonably available from the aquifer. There are 900 new residents moving to Florida PER DAY! Yes, you read that correctly. To meet the rapid influx of new residents, urban redevelopment has placed greater demands on consumptive use and aquifer withdrawal. Urban sprawl (which has never been successfully addressed in Florida) has claimed as its victim thousands of acres of land that Florida needs for recharge.
Science and Engineering Behind pureALTA
The City collaborated with the St. Johns River Water Management District (SJRWMD) through a cost-share program for innovative projects within its district. SJRWMD is one of five regional water management districts in the state responsible for allocating water supply among other responsibilities. The District funded 50 percent of the $1 million cost for construction and initial start-up operations and testing of the pilot project. Through a competitive consultant selection project, the City hired Carollo Engineers to design and manage pureALTA’s initial operational testing. pureALTA has lower energy requirements than RO and does not generate a waste brine stream.
The pilot operated for an initial one-year period under the SJRWMD grant program to evaluate and test the system. Treatment goals for the pilot include:
- Elimination of pathogens,
- Meeting or exceeding primary and secondary drinking water standards, and
- Meeting or exceeding recommended limits on constituents of emerging concern (CECs).
In addition to regulated constituents and CECs, the City also included state of the art quantitative and qualitative analytics like in-vitro bioassays and non-target analysis which served to examine the unregulated “unknowns” in the finished water. These bioassays included measurement of estrogen-like chemicals and androgen-like chemicals, among others.
The findings of the pureALTA project include:
- Water quality: The selected process train consistently met all pathogen and chemical water quality standards and health-based criteria being applied to potable reuse projects in the United States. This was achieved without the generation of a brine stream.
- Project costs: Capital and operating costs for a future 0.3 mgd and 0.5 mgd full-scale DPR facility were developed to compare a membrane (RO) to the O₃/BAF based processes, with the O₃/BAF based processes being more energy efficient and yielding 30% to 50% overall cost savings.
- Demonstrated advanced monitoring technologies
- Data-sharing: FDEP was included in the project from project initiation through development of the sampling plan, and a summary presentation of the project findings. The City is sharing data with the Potable Reuse Commission, a stakeholder group that is developing a regulatory framework for potable reuse in Florida.
- Education: The City created the Altamonte Springs Science Incubator (AS2I) program provides middle and high school students hands-on access to our innovative projects. Through this public/private partnership between the City, Seminole County Public Schools, Duke Energy, Advent Health, we are slowly demystifying what potable reuse really is and where it comes from for future generations who will use potable reuse in their daily lives.
Unlike many of the potable reuse pilot studies and projects being done, the City owns the pureALTA equipment which means the public owns pureALTA. There are no trademarks, copyrights or patents that stand in the way of other communities adopting our process as their own and making it better! To us, pureALTA is much like open-source architecture. All of us innovating together will produce exponentially dynamic benefits for future citizens of the world.
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