The Environmental Protection Agency (EPA) announced a draft National Water Reuse Action Plan that identifies priority actions supporting the reuse of water for human consumption, agriculture, business, industry, recreation and healthy ecosystems. Items proposed in the draft will require the collaboration between governmental and nongovernmental organizations to implement the actions.
What is Water Reuse?
Water reuse is an innovative and dynamic strategy that can dramatically change the future of water availability in the U.S. Water reuse can be used to meet water demands and mitigate the risks posed by droughts. Recycled water can be used for a wide variety of applications, including agriculture, potable water supplies, groundwater replenishment, industrial processes and environmental restoration. The water reuse process can stem from sources such as industrial process water, agricultural return flows, municipal wastewater, oil and gas produced water, and stormwater.
Why Implement a Water Reuse Action Plan?
The draft National Water Reuse Action Plan is the first initiative of its kind to be coordinated across the water sector. According to EPA’s Assistant Administrator for Water, David Ross, forty states anticipate shortages of fresh water within their borders over the next decade. Water reuse has the potential to ensure the viability of our water economy and provide safe and reliable drinking water for years to come.
After extensive research and outreach, it was determined that meaningful advancement of water reuse would best be accomplished by working cooperatively with all water sector stakeholders including federal, state, tribal, and local water perspectives. The EPA hopes to issue a final plan that will include clear commitments and milestones for actions that will increase the sustainability, security and resilience of the nation’s water resources.
What Does the Plan Entail?
The draft National Water Reuse Action Plan identifies 46 proposed actions across ten strategic objectives.
Enable consideration of water reuse with integrated and collaborative action at the watershed scale.
Coordinate and integrate federal, state, tribal, and local water reuse programs and policies.
Compile and refine fit-for-purpose specifications.
Promote technology development, deployment, and validation.
Improve availability of water information.
Facilitate financial support of water reuse.
Integrate and coordinate research on water reuse.
Improve outreach and communication on water reuse.
Support a talented and dynamic workforce.
Develop water reuse metrics that support goals and measure progress.
The EPA is soliciting public input through a 90-day public comment period. This period will seek to:
Identify the most important actions to be taken in the near term.
Identify and describe the specific attributes and characteristics of the actions that will achieve success.
Secure specific commitments to lead/partner/collaborate on implementation of actions.
Climate Change Brings New Innovation to the Water Environment
The summer of 2018 saw devastating fires blazing all over the world. Nearly 100 people died in raging fires across the southern coast of Greece. More than 50 wildfires scorched Sweden where the temperature north of the Arctic Circle soared into the 90’s causing drought conditions. Record breaking temperatures across the globe from Montreal to Great Britain topped 98 degrees this summer. In Japan, 22,000 people were hospitalized when temps climbed to 106 degrees. And, in normally cool Oslo, the thermometer climbed to 86 degrees for 16 consecutive days. From Southern California and Arizona to India and Pakistan, withering heat reached a deadly 110 degrees that parched the environment.
The most alarming news is the hottest temperature ever reliably recorded reached 124.3 degrees in Algeria this July.
Fires, heat and drought of this scope and scale seem to be becoming the new normal. These extreme events point to a planet that is warming and perhaps faster than scientists have predicted.
Although the effects of climate change may vary widely in different geographic regions, those areas already hardest hit with drought and arid conditions may be in the most critical need of clean drinking water.
This crisis will only get worse as the earth’s population conceivably could grow exponentially in the next 50 years and adequate supplies of water become even more scarce. In addition to supplying all these thirsty people with clean water, the chilling paradox is the increased demand on already-scarce resources means there is a greater chance that existing water sources will become polluted by human waste, industrial toxins, and contaminated agricultural runoff.
It is human nature to postpone change and sacrifice as long as possible. But it is clear that public service announcements warning residents to save water, take shorter showers, plant resilient gardens, and conserve, is not going to be enough to help avoid a global water shortage. Fortunately, scientists and researchers are working diligently to solve some very complex problems to provide innovative and sustainable clean water solutions for the future.
Here are three cutting edge ideas for sustainable water supplies that just may help a warming world.
Ancient Bacteria for Modern Water Purification
Anaerobic or oxygen-averse bacteria to treat wastewater is back in vogue… after a billion years. When the earth was a toxic primordial goo, anaerobic bacteria thrived in the oxygen deprived world forming the first signs of life. Environmental engineers at Stamford University are now bringing back these ancient microorganisms as a more cost-effective wastewater treatment process.
Wastewater treatment plants that use aerobic bacteria must provide oxygen with huge and costly electrically powered blowers for these microorganisms to survive. Anaerobic bacteria treatment processes do not need oxygen and use considerably less energy, making the wastewater treatment process more economical to operate. In addition to saving money, engineers believe these anaerobes can filter household and industrial chemicals better than conventional treatment plants.
Full-scale plants utilizing anaerobic bacteria may soon be capable of processing millions of gallons of wastewater per day into refreshing clean water.
Mega Scale Desalination
Desalination plants may not have been around as long as ancient bacteria, but this technology is not a new concept either. What is news however, is the increasing role desalination will have in the future. Israel’s Sorek desalination plant is the largest seawater reverse osmosis (SWRO) desalination plant in the world providing 627,000 cubic meters per day (m3/d) or the equivalent to about 166,000,000 gallons of water per day (gpd) to Israelis.
Desalination plants which were notoriously expensive energy hogs have become less energy-intensive as technologies have improved. Using renewable energy, such as solar, wind and geothermal along with advanced technologies including thin-film nanocomposite membranes, captive deionization (most suitable for brackish water), forward osmosis, and metal–organic framework (MOF) biological cell membranes that requires very little water pressure, water desalination is becoming more efficient and cost effective. The new cutting-edge membranes can even filter out precious metals such as lithium used in batteries.
Saudi Arabia, the largest producer of desalinated water in the world with its 32 desalination plants and growing, will soon be producing a historic 5 million m3/d or the equivalent of about 1,321,000,000 gpd, a global record of desalinated water. Benefiting from this leading-edge technology, Cape Town South Africa may have averted a catastrophic “Day Zero” when the City’s first desalination plant went online, preventing a water doomsday for its residents.With the world’s oceans holding about 96.5 percent of all Earth’s water and with more innovation, desalination may prove to be this thirsty world’s salvation.
Drinking Water from the Air
Another old idea that is gaining favor is converting fog into drinking water. Super-sized moisture collection systems could allow people living in coastal or mountainous areas to convert fog into safe drinking water. Collection traps are made from a 3D mesh that can withstand high wind speeds, while still retaining and accumulating water in storage tanks. With a variety of sizes available, these fog systems can be used for individual needs or supplying water for entire villages.
Combine this idea with giant Atmosphere Water Generators (AWG), which takes moisture or humidity directly out of the air and converts it into potable water. Even in the driest of lands, the air is loaded with water molecules and enough drinking water converted from AWG’s could provide communities with a continuous and sustainable source of clean water.
On a large scale, the AWG units can be mounted on the roof-tops of commercial or residential buildings. When powered by renewable energy, these systems can create safe local drinking water efficiently and economically. Water districts and municipalities managing these units, can provide as much as 55 m3 /d or about 14,500 gallons per day, enough to service each building independently with water.
Collected water from both fog collection systems or AWG’s may seem farfetched. But consider this, 80 percent of California’s water goes to irrigate farms and the other 20 percent of water use goes to urban use. Collected water from the air could be used to irrigate crops or other commercial watering needs.
Water conservation and alternative technologies such as fog collection systems and AWG units can supplement our increasing demand for clean water and these ideas just might may make a difference.
The Future is for Innovation
Combating climate change and managing our depleting water resources is a reality we can’t ignore. The devasting fires, drought and heat from 2018, is a reminder that our actions today may help avert a global catastrophe in the future. These innovative ideas and others still in development are one step forward to a more sustainable world.
Reclaiming Wastewater on the Space Station has an impact right here on Earth!
Water—it’s essential for all living beings… and water is essential to make life possible. It’s an interesting paradox that has kept scientists searching for life in extreme places.
When NASA recently announced the discovery of liquid water flowing under an ice cap on Mars, it opened the exciting possibility that life may exist outside our earthly abode. While it is conceivable scientists may eventually discover life somewhere in our galaxy, a reliable source of water outside earth is fundamental for the possibility of establishing a colony on Mars, exploring the universe and even visiting distant planets in search of life outside earth.
This is the stuff of science fiction…or is it?
Well, let’s get the stars out of our eyes and return to earth. First, we need to get to Mars and therein lies the challenge. Top on the list is how to provide the essentials for life, such as water, air and the entire habitat for the astronauts to live in as they journey among the stars.
Getting to Space
Establishing a sustainable long-term flight program requires a base to launch manned operations in space. The International Space Station (ISS), which was put into orbit in 1998 and has been continuously occupied since 2000, currently provides a habitable place for astronauts to live and conduct scientific experiments.
But hauling tons of supplies and materials to the International Space Station (ISS) is inefficient and extremely expensive. Sustaining a crew of four astronauts on the ISS with water, power and other supplies, costs nearly one million dollars a day. Even with the reusable SpaceX rocket which regularly provides supplies to the ISS, it costs $2,500 per pound to launch into space. With four astronauts living on the ISS needing approximately 12 gallons of water a day, it is impractical to stock the ISS with the tons of water needed for long periods of time.
It’s no wonder then that rationing, and recycling is an essential part of daily life on the ISS. The Space Station must provide not only clean water, but air to breath, power, and ideal atmospheric conditions to sustain life outside earth.
And every drop of liquid is important!
Reclaiming Water for Life Support
The Environmental Control and Life Support System (ECLSS) on the ISS is a life support system that provides atmospheric pressure, oxygen levels, waste management and water supply, and fire detection and suppression. The most important function for ECLSS is controlling the atmosphere for the crew, but the system also collects, processes, and stores waste and water produced by the crew…including the furry lab passengers too.
Yes, even mice waste is recycled.
If the idea of drinking reclaimed water from mice urine and other waste sources sounds unappetizing, consider this, the water the astronauts drink is often cleaner that what many earthlings drink. NASA regularly checks the water quality and it is monitored for bacteria, pollutants and proper pH (60 – 8.5).
This highly efficient reclamation system processes and recycles fluid from the sink, shower, toilet, sweat, and even condensation from the air. The ECLSS water recovery system on the ISS uses both physical and chemical processes to remove contaminants, as well as filtration and temperature sterilization to ensure the water is safe to drink.
More Innovation for the Future
Providing the astronauts with clean water from reclaimed wastewater at the Space Station is working fine for what they need right now, but it’s not perfect. The ISS system recovers water at a rate of approximately 74 percent. For longer missions to Mars and beyond, this rate must increase to at least 98 percent to sustain longer journeys into space. Scientists are continuously working on better and more efficient close-looped support systems to reduce water loss and improve ways to reclaim water from all waste products.
Recently, NASA invested in a new, lower cost solution to biologically recycle and reuse water developed by Pancopia. Pancopia is a small environmental and energy engineering company located in Virginia that focuses on wastewater treatment and research and development projects. Engineers at the firm have discovered an innovative technology that makes use of a group of bacteria called anammox. Anammox when combined with two other types of bacteria commonly used in conventional wastewater treatment (nitrifiers and denitrifiers), can remove high levels of organic carbon and nitrogen, the two primary pollutants in wastewater.
The combination of these three organisms naturally adjust to changes in the system and eliminates pollutants faster and more reliably than traditional wastewater treatment operations. And, the cost is significantly less to operate than conventional systems, which requires a lot of energy and consumables to run. In addition, the stability of the anammox process reduces costs by requiring fewer manpower hours to monitor and operate.
Back on Earth
What does all this water and wastewater reclamation innovation mean for us on earth?
Pancopia is currently working on a similar system used on the ISS for municipal wastewater facilities. Using the technology developed for the Space Station, other areas in the world with limited access to clean drinking water, will soon be able to utilize this advanced water filtration and purification system.
This innovative water recycling system initially intended for the astronauts, now has the potential to cut treatment expenses to less than half the current costs for municipal customers, while providing sustainable crystal-clear drinking water especially in arid and drought-stricken communities across the globe.
Man’s search for extraterrestrial life and desire to travel through space may actually have its greatest impact right here on Earth—clean water!
The Massachusetts Department of Environmental Protection (MassDEP), is now accepting Project Evaluation Forms (PEFs) for new drinking water and wastewater projects seeking financial assistance in 2019 through the State Revolving Fund (SRF). The SRF offers low interest loan options to Massachusetts cities and towns to help fund their drinking water and clean water projects. PEFs are due to the MassDEP Division of Municipal Services by August 24, 2018, 12:00 PM.
Financing for The Clean Water SRF Program helps municipalities with federal and state compliance water-quality requirements, focusing on stormwater and watershed management priorities, and green infrastructure. The Drinking Water SRF Program, provides low-interest loans to communities to improve their drinking water safety and water supply infrastructure.
This year, the MassDEP Division of Municipal Services (DMS) announced the following priorities for SRF proposals.
Water main rehabilitation projects which include full lead service replacement (to the meter) – this is a high priority for eligibly enhanced subsidy under the Drinking Water SRF.
Reducing Per- and polyfluoroalkyl (PFAS) contaminants in drinking water.
Asset Management Planning to subsidize Clean Water programs.
Stormwater Management Planning for MS4 permit compliance and implementation.
Summaries of the Intended Use Plans (IUP), will be published in the fall, which will list the project name, proponents, and costs for the selected projects. After a 30-public hearing and comment period, Congress will decide which programs may receive funding from the finalized IUPs.
To Apply for SRF Financing
Tata & Howard is experienced with the SRF financing process and is available to help municipalities develop Project Evaluation Forms along with supporting documentation, for their local infrastructure needs.
Please contact us for more information.
The MassDEP Division of Municipal Services are accepting Project Evaluation Forms until August 24, 2018 by 12:00 PM.
We Can Help
For more information on the MassDEP State Revolving Fund and assistance preparing a PEF contact us.
Health Advisory Guidelines for Per- and polyfluoroalkyl Substances Detected in Public Water Systems
The Massachusetts Department of Environmental Protection (MassDEP) announced in early June, and through the Office of Research and Standards (ORS), its recommendations on the Unregulated Contaminant Monitoring Rule 3 (UCMR 3) for emerging contaminants-specifically Perflourinated Alkyl Substances (PFAS).
PFAS or Per- and polyfluoroalkyl substances are a group of man-made compounds that include perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perffluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), perflouroheptanoic acid (PFHpA), and perfluorobutane sulfonate (PFBS).
According the Environmental Protection Agency (EPA), all these UCMR 3 PFAS compounds have been detected in public water supplies across the US. Since PFAS are considered emerging contaminants, there are currently no established regulatory limits for levels in drinking water. However, in 2016, the EPA set Health Advisory levels (HA) of 0.07 micrograms per liter (µg/L) or 70 parts per trillion (ppt) for the combined concentrations of two PFAS compounds, PFOS and PFOA.
MassDEP’s ORS established drinking water guidelines that follows the EPA’s recommendations for health advisory levels at 70 ppt, which applies to the sum total of five PFAS chemicals – PFOS, PFOA, PFNA, PFHXS, and PFHpA. And, if the level of contamination poses unacceptable health risks to its customers, Public Water Systems (PWS) must take action to achieve safe levels. They also must provide public notice.
The EPA and MassDEP’s recommended guidelines for PFAS include:
Public Water Suppliers take immediate action to reduce levels of the five PFAS to be below 70 ppt for all consumers.
Susceptible health-risk groups (pregnant women, infants, and nursing mothers) should stop consuming water when the level is above 70 ppt.
Public Water Systems must provide a public Health Advisory notice.
The EPA also recommends that treatment be implemented for all five PFAS when one or more of these compounds are present.
Although, PFAS are no longer manufactured in the United States, PFAS are still produced internationally and can be imported in to the country1. PFAS have been in use since the 1940’s and are persistent chemicals that don’t breakdown, accumulate over time in the environment and in the human body. Evidence shows that prolonged exposure PFAS can have adverse effects on human health and the ecology.
PFAS can be found in:
Agricultural products grown in PFAS-contaminated soil or water, and/or handled with PFAS-containing equipment and materials.
Drinking water contaminated from chemical groundwater pollution from stormwater runoff near landfills, wastewater treatment plants, and firefighter training facilities2.
Household products, including nonstick products (e.g., Teflon), polishes, waxes, paints, cleaning products, and stain and water-repellent fabrics.
Firefighting foams2, which is a major source of groundwater contamination at airports and military bases where firefighting training occurs.
Industrial facilities that manufactured chrome plating, electronics, and oil recovery that use PFAS.
Environmental contamination where PFAS have built-up and persisted over time – including in fish, animals and humans.
While most states are relying on the EPA’s Health Advisory levels (including Massachusetts), some, such as Connecticut, Minnesota, New Jersey, Arizona, and Colorado have addressed other UCMR 3 PFAS pollutants as well.
Most research on the effects of PFAS on human health is based on animal studies. And, although there is no conclusive evidence that PFAS cause cancer, animal studies have shown there are possible links. However, PFAS ill-health effects are associated with changes in thyroid, kidney and liver function, as well as affects to the immune system. These chemicals have also caused fetal development effects during pregnancy and low birth weights.
PFAS are found at low levels throughout our environment—in foods we consume and in household products we use daily. PFAS in drinking water at levels higher than the EPA’s recommendations does not necessarily mean health risks are likely. Routine showering and bathing are not considered significant sources of exposure. And, while it is nearly impossible to eliminate all exposure to these chemicals, the risk for adverse health effects would likely be of concern if an individual continuously consumed higher levels of PFAS than the guidelines established by the EPA’s Health Advisory.
MassDEP is continuing its research and testing for PFAS in Public Water Systems. Large Public Drinking Water Systems have already been tested and sampling indicated that approximately 3% had levels of PFAS detected. MassDEP is currently working with smaller Public Water Systems to identify areas where PFAS may have been used or discharged to the environment.
As more information and regulations develop on this emerging contaminant, MassDEP will continue to communicate their findings. Tata & Howard is also available for any questions that may arise, as well as, assist with testing and recommend treatment options for our clients.
1 In 2006, the EPA and the PFA industry formed the PFOA Stewardship program to end the production of PFAs.
2 MassDEP in partnership with the Massachusetts Department of Fire Services (MassDFS), announced in May a take-back program to remove hazardous pre-2003 firefighting foam stockpiles and be neutralized. Manufacturers stopped making PFAS foam in 2002 and have since developed fluorine-free and more fluorine stable foams that are safer to the environment.
Here’s a problem that nobody wants to mess with, clogged toilets, backed up sewer systems, and the costly repairs to fix this stink.
While there are many obvious things not to flush down the toilet, an astonishing amount of non-flushable wipes, paper products, dental floss, and other dispensable hygiene products are flushed down toilets every day. This has contributed to cities and municipalities dealing with chronic clogged sewer systems and expensive wastewater treatment maintenance, not to mention homeowners who face the inconvenient problem of having a toilet back up in their home.
These raw sewage messes aren’t pretty and are not easy or inexpensive to fix.
Here’s the indispensable truth about what goes down the toilet.
Even though many items can be flushed down the toilet, it’s misleading to believe that everything is ‘flushable’ and safe for our sewer systems and environment. The journey is just beginning when that swirling eddy of water makes everything in the toilet bowl disappear.
All the solids flushed down the toilet that don’t dissolve, eventually end up at a wastewater treatment facility. Traveling miles and miles through pipes underneath our streets and sidewalks, this raw sewage flows by gravity or with the help of pump stations towards a wastewater treatment facility. Most of this waste is taken care of, out of sight, by Municipalities who work every day to maintain this process.
However, the pump stations are periodically clogged by non-disposable waste that is flushed down the toilet. Products that are designated as ‘non-flushable’ are often made with plastic fibers and do not break down in wastewater systems. Even products that are labeled as ‘flushable’, do not easily disintegrate in water like toilet paper.
For example, popular flushable personal care wipes (for both babies and adults) are marketed as a convenient, portable, and a hygienic way to keep clean. Manufacturers claim these flushable wipes are septic-safe or safe for sewer systems. The problem is these products take much longer to break down as compared to traditional toilet paper.
And, here’s the reason why.
A well-known manufacturer of flushable wipes claims their product passes what is called a ‘slosh’ distribution test. The wipes, which are made of ‘non-woven clothlike material’, must be strong enough to handle the manufacturing process, hold up while being used, and still be weak enough to break apart after being flushed down the toilet.
The slosh test checks the potential for wipes to break down in water during agitating conditions. A box containing water and one or more wipes tips back and forth, slowly and repeatedly “sloshing” the wipes for three hours. All fibers from the test are strained from the slosh box and then poured through a 12½-millimeter sieve (consistent with industry guidelines) and rinsed for two minutes to measure the percentage of fiber material that passes through the sieve.
The problem is, unlike toilet paper that quickly disperses in circulating water, the tightly woven fabric of the wipes takes much longer to breakdown (as noted in the slosh test), and while these products may not clog pipes immediately, imagine everything flushed down the toilet snagging on it, expanding, and gathering together to clog pipes and sewage pumps.
Private and municipal sewer system operators end up sifting through what’s left in the wastewater to clear these obstructions—often costing millions of dollars to maintain and repair.
Sadly, many of these disposable products are regularly flushed down the toilet. In a recent study, more than 98 percent of what was found at a wastewater treatment plant was non-flushable personal care wipes, paper towels, dental floss, diapers, tampons, condoms, cleaning wipes and other ‘trash’ not intended to be flushed.
And there are many more flushing no-nos—seemingly harmless and not so harmless items regularly flushed down the toilet.
Here is a list of things never to flush:
Baby wipes and diapers (including types labeled ‘flushable’ or ‘disposable’): Diapers can take up to 500 years to degrade in a landfill. These highly absorbent synthetic materials are slow to breakdown and can block sewer systems.
Paper towels: Just like wipes, these common household items are designed to not breakdown when wet and absorb liquids.
Cotton balls, cosmetic pads and cotton swabs: These items tend to gather in pipe bends causing blockages.
Dental Floss: This little string can cause havoc to plumbing and sewer systems.
Medications or Supplements: Wastewater treatment facilities are not designed to breakdown pharmaceuticals. While drugs may dilute in the waste stream, studies have shown the presence of medicines such as steroid hormones and antidepressants in wastewater effluent. The EPA1 refers to this as “Personal Care Products as Pollutants,” which also includes residues from cosmetics, agribusiness, and veterinary use.
Medical Supplies: Razors, bandages and hypodermic needles are often flushed, but quite simply, they don’t degrade. The razor blades and needles also present a danger to employees who need to remove the items that clog the system.
Rubber: Items such as latex gloves and condoms, are made of a material that is not intended to breakdown in liquid.
Cat litter (including types labeled ‘flushable’): The absorbent properties of litter (generally clay and sand) are designed to ‘clump’ and will clog sewer systems.
Feminine Hygiene Products (sanitary napkins, tampons and applicators): Like cat litter, these products are designed to absorb liquids and swell in the process, clogging pipes, get stuck in bends and block sewer lines.
Fats, oil, and grease: Known in the wastewater industry as ‘FOG,’ are liquids that solidify when cooled, and this creates significant problems for public wastewater systems, as well as drains in your home.
Hair: Like dental floss, flushed hair can cause tangled blockages ensnaring everything that passes by.
Food products: banana peels, apple core, leftovers. While these may degrade over time, food products simply do not disintegrate fast enough and can cause blockages throughout the system.
Trash of any kind: All this litter does not easily biodegrade.
Candy and other food wrappers
Chemicals: paint, automotive fluids, solvents, and poisons, are just terrible pollutants to flush. Just as wastewater treatment plants are not designed to screen out pharmaceuticals, these facilities are not designed to eliminate toxic chemicals.
Heavy Metals: These pollutants include, mercury, cadmium, arsenic, lithium (think batteries) and lead, etc. Please dispose of any of these toxins properly to prevent harm to the environment and the potential for serious health risks.
Flushable toilets and the wastewater facilities that treat our raw sewage are indispensable services in modern life. It’s long time we take responsibility and think twice about what is flushed down the toilet—for the sake of our sewers systems and wastewater treatment processes, and our indispensable precious environment.
Here in the US, we are fortunate to have access to clean water everyday—just turn on the tap and out pours some of the safest treated water in the world. But the water we take for granted every day—to brush our teeth, take showers, flush the toilet and for so many other reasons, is increasingly rising in cost. Continue reading Plugging the Leak on Rising Water Costs
Abstract: The Towns of Canaan, Vermont and Stewartstown, New Hampshire operate a shared wastewater treatment facility, which required significant upgrades. The existing facilities were 40 years old and although a few upgrades were performed in the 90s, the facilities were not performing well, did not meet Life Safety codes, and required significant maintenance. The economical upgrade met all of the goals of the Client by providing for simple operation and maintenance requirements, meeting the Life Safety codes, eliminating confined spaces, lowering of electrical power costs, and meeting discharge parameters through production of high quality effluent.
As those in the industry well know, water and wastewater treatment plants use an exorbitant amount of energy. In fact, 30-40% of total municipal energy consumption is due to water and wastewater treatment plants. In addition, energy currently accounts for 40% of drinking water systems’ operational costs and is projected to jump to 60% within the next 15 years. This excessive energy consumption places financial burden on already stressed water and wastewater utilities struggling to keep up with ever-increasing regulations and demand.
The Electric Power Research Institute (EPRI) conducted studies on wastewater treatment plants and cautions that as treatment requirements increase, energy requirements will also increase. EPRI also projects that as treatment requirements increase, the energy required to treat wastewater utilizing conventional technologies will increase exponentially. For example, new membrane bioreactor (MBR) processes actually consume 30-50% more electricity than plants that utilize more advanced treatment with nitrification. Also, plants that incorporate nanofiltration or reverse osmosis to meet stringent effluent utilize nearly twice the energy. EPRI further projects that strict nitrogen and phosphorus removal will be increasingly required, necessitating the incorporation of these energy-intensive technologies.
And let’s not forget the environment. Drinking water and wastewater systems add over 45 million tons of greenhouse gases annually, contributing to the already problematic issue of climate change. Bringing the issue full circle, climate change directly affects both the availability and the quality of our drinking water supply. The importance of incorporating energy efficiency into water and wastewater operations is paramount to these systems’ future sustainability.
Canaan, VT and Stewartstown, NH Shared Wastewater Treatment Plant Upgrades
The Towns of Canaan, Vermont and Stewartstown, New Hampshire operate a shared wastewater treatment facility, which required significant upgrades. The existing facilities were 40 years old and although a few upgrades were performed in the 90s, the facilities were not performing well, did not meet Life Safety codes, and required significant maintenance.
One of the primary elements of the design was the consideration of the economics of energy reduction. The design incorporated insulated concrete form construction for the building walls with R-49 insulation rating in the ceilings. The design also included a wood pellet boiler with a pellet silo and hot water heating system, which allowed for reduction of explosion proof heaters in the headworks building. All of the windows were low-E and highly insulated, and an outer glassed-in entry way increased the solar gain retention of the building and reduced heat loss. The process headworks and operations buildings were constructed as single story structures, increasing operator safety. The lagoon aeration system is now a fine bubble, highly efficient process with additional mixing provided by solar powered mixers that help reduce aeration requirements, improve treatment, and allows for the addition of septage, all at no cost due to solar power.
The pump station upgrades were designed to eliminate daily confined space entry by the operator by the conversion to submersible pumps. For sludge removal, a unique and simple “Sludge Sled” system was incorporated, which allows the operators to easily remove the sludge at their convenience. Sludge treatment is accomplished with a geo-bag system that allows the sludge to be freeze dried, reducing the volume by almost 50% with no energy consumption. The influent pump station was designed with three pumps instead of the normal two-pump system in order to meet both present and future design flows, allow for lower horsepower pumps, improve flexibility, reduce replacement costs, and reduce energy costs. The other four deep dry pit pump stations were converted to wet wells and submersible pumps, eliminating confined spaces, and are equipped with emergency generators, eliminating the need for operator attention when power is lost.
The incorporation of highly energy efficient building components resulted in reducing annual operation and maintenance costs, which resulted in a more sustainable facility. All of the equipment and processes were thoughtfully selected to reduce both annual and future replacement costs.
The treatment system is a 3-cell aerated lagoon system, and the solar powered mixers were installed to enable reduction of the aeration needs and horsepower during the summer months when septage is added. The aeration blowers, which are housed in insulated enclosures, reduce noise and were sized to allow for the addition of septage to the lagoons, which is not common in Vermont. The aeration blowers are controlled with Variable Frequency Drives (VFDs), which allow for greater operator control of aeration and provide energy cost savings. The operation is simple and safe for operators and others who need to maintain the facility and equipment. The design has provided flexibility to the operators and has resulted in an energy efficient, sustainable solution for this community.
Shrewsbury, MA Home Farm Water Treatment Plant Design
The Home Farm Water Treatment Plant (WTP) in Shrewsbury, Massachusetts was originally constructed in 1989. Although the WTP is still fully functional, its treatment capabilities are limited to chemical addition and air strippers for VOC removal, and the plant is capable of treating 6.0 million gallons per day (mgd). Manganese is present at all Home Farm wells, with widely varying levels from a low 0.03 parts per million (ppm) to a high 0.7 ppm. The existing treatment plant sequesters manganese, but does not have the ability to remove it from finished water.
Three treatment methodologies were piloted. The first two were greensand and pyrolucite, both commonly implemented catalytic media options for removing manganese and iron. The third was Mangazur®, a new technology. Mangazur® filter media contains the microscopic organism leptothrix ochracea, which consumes manganese and is naturally occurring in groundwater. Through consumption, the microbes oxidize the manganese to a state where it can precipitate onto the media. Unlike other media, Mangazur® does not require regeneration due to the continuous growth of microbes within the filter. Mangazur® technology also does not require chemical addition for pre-oxidation, minimizing the amount of chemical required for the plant.
Pilot testing for the biological treatment was performed over five one-week trials. Test parameters included a long shut-down on the filters, adding pre-oxidant, and adjusting pH or dissolved oxygen. The results of the testing indicated that although the Mangazur® does require a correct dissolved oxygen level and pH, it does not require a pre-oxidant, making the only chemical addition necessary for pretreatment potassium hydroxide for pH adjustment. Filter backwash efficiency is also a major benefit of the Mangazur® technology for the Home Farm application. With loading rates twice that of traditional catalytic media and filter runs exceeding 96 hours, the Town would only need to backwash the four filters once every four days rather than eight filters every day, saving a significant amount of water. The backwash flow rate and duration are also significantly lower for Mangazur® filters than for other traditional filter options. The results of the pilot tests indicated that all technologies were viable options to reduce manganese levels below 0.05 ppm; however, the biological treatment was the most efficient option.
Since the existing chemical feed equipment in the plant is aging and the existing building itself was also in need of rehabilitation, the decision was made to construct an entirely new standalone 7.0 mgd facility. The new facility will feature many energy efficient features including translucent panels for lighting efficiency, high efficiency water fixtures, high efficiency lighting, and stormwater bioretention areas for drainage. In addition, while the existing building will be demolished, the concrete slab slab will be kept for future installation of solar panels. The new facility also contains three deep bubble aerators for VOC removal. While Mangazur® technology has been approved in one other municipality in Massachusetts, there are few treatment plants in the northeast using this technology, and of those treatment plants, none have a design capacity above 5.0 mgd. Home Farm has a much higher design capacity and will be the largest Mangazur® water treatment plant in the northeast once completed. The Mangazur® filters at Home Farm will have the second highest design capacity in the country, after a 26.0 mgd treatment plant in Lake Havasu City, Arizona.
Tata & Howard provides on-call engineering services for water, wastewater, and energy related projects for the City of Flagstaff, Arizona. Several options for replacement of the blowers were evaluated and presented to the City in a report that recommended the installation of appropriately sized turbo blowers and upgrading the controls logic to automate dissolved oxygen controls.
The City had been experiencing long term maintenance issues with the existing biogas piping at the Wildcat Wastewater Reclamation Facility. The piping to the co-generator was not providing an adequate supply of gas from the digesters which, if operating, could save the City approximately $200,000 in annual power costs. The goals of this project were the restoration of the ability to run the generator on biogas, utilize the heat generated by the sludge digestion process to further reduce energy costs, reduce maintenance time to operate the biogas system, and have a positive impact on the environment, since methane is one of the most potent greenhouse gases.
In addition, Tata & Howard conducted an energy efficiency study on the aeration blowers and pumps at two treatment plants. Pumping systems had efficiencies as low as 20%. Pumps and blowers were oversized to meet peak and future demands but not efficient at low flows or off peak flows. The testing showed that modifications to these systems had the potential to save the City approximately $250,000 in annual electrical costs and $445,000 in APS rebate funds for the modifications.
While these three case studies are all extremely different projects, the goals are the same: increased energy efficiency, greener operations, and sustainability, all while meeting project objectives, budgets, and deadlines. Increasing energy efficiency in water and wastewater treatment is no longer optional; rather, it is a necessity to remain operational by meeting both budgetary and sustainability objectives. By incorporating innovative thinking and tailored methodologies into rehabilitation and repair projects, water and wastewater systems can ensure sustainable operations and a greener environment while protecting our world’s most precious resource for generations to come.
Municipal wastewater treatment requires an enormous amount of energy, which comes at a high cost, both fiscally and environmentally. Energy costs continue to rise while municipal budgets shrink, creating unsustainable operating costs. Indeed, energy efficiency for wastewater utilities is no longer a choice, but a necessity. The good news is that there are many relatively inexpensive and easily implemented ways of controlling energy costs at wastewater treatment facilities, and the payback period can easily justify the investment.
The first step towards making an informed decision about energy efficiency at a wastewater treatment facility is an energy audit. A quality wastewater energy audit takes into account energy efficient equipment replacement, operational changes, and process control, and includes conducting on-site observations, testing wastewater systems and equipment, and monitoring power costs and usage. The result of a well executed energy audit is a justifiable plan of action that provides optimal energy savings, a true road map to energy efficiency.
Once the audit results are in, a number of changes, both large and small, can be made to save on energy costs. Wastewater treatment plants can conserve energy in many ways, from changing light bulbs and upgrading motors to installing combined heat and power systems and other renewable energy technologies. Some energy efficient options are highlighted below:
Equipment & Collection System Upgrades
Variable-frequency drives (VFDs) modify the speed of electric motors by adjusting the amount of power being delivered. These precise drives adjust motor speed to match the exact energy demand needed at any given time. By controlling the amount of power used, VFDs provide significant cost savings to wastewater treatment facilities and to the environment. A good application for VFDs is the blowers on the aeration system. Dissolved oxygen probes installed in the aeration basin can provide real time measurement of oxygen concentration in the wastewater. This information can be sent to the VFDs to speed up or slow down the blowers to provide only the oxygen needed for the biological process to thrive. The result — significant savings and happy microbes.
Heating, Cooling, and Ventilation Systems
Updated HVAC systems that incorporate energy-efficient technologies provide operational savings and reduce energy consumption. Like VFDs, the most cost-effective time to upgrade these systems is when they are already due for replacement.
Energy Efficient Lighting
Installing energy efficient lights and lighting systems is one of the easiest ways to increase energy efficiency at wastewater utilities. Replacing burnt-out lights with fluorescents or LEDs eases into the transition and makes it affordable. Dimmers, motion sensors, and time switches can be installed to save even more energy — and money.
Electrical Load Management
Strategies such as improving the power factors of motors, reducing peak demand, and shifting to off-peak hours all provide significant savings for wastewater treatment facilities.
Biosolids, or the solid organic matter that is a by-product of the wastewater treatment process, should be managed sustainably in order to reduce both environmental and economic costs. Sustainable biosolids management incorporates efficient methods of treatment, transport, and end-use. By implementing a sustainable biosolids management plan, such as pretreatment for minimizing sludge treatment and recycling/reuse of residual sludge, municipalities can reduce greenhouse gases as well as trucking miles, thereby saving money and generating energy.
While updating equipment is a great way to increase energy efficiency, even more important is training managers and staff to think and operate efficiently. Educating wastewater utilities’ staff on the importance of energy conservation and on best practices yields significant savings for wastewater utilities and the environment.
Inflow and Infiltration Management
Inflow and infiltration (I/I) in a wastewater facility’s collection system results in significantly higher costs to utilities. Increased flow requires additional processing, and results in higher demand to lift station pumps. In addition, systems are at an increased risk of becoming overloaded. Controlling I/I is a key step to becoming a more efficient wastewater treatment facility.
Energy Efficient Technology
Combined Heat and Power
Combined heat and power (CHP), or cogeneration, is a clean, efficient, and sustainable approach to generating power from a single fuel source. Wastewater treatment plants with anaerobic digesters installed produce methane gas as a by-product of digestion. Traditionally, these facilities convert the methane to carbon dioxide and release it into the atmosphere. However, a cleaner and more efficient way of managing methane is to actually utilize it as an energy source. CHP systems are designed to meet the specific energy needs of wastewater treatment plants, and can significantly enhance operational efficiency while decreasing energy costs. In addition, CHP systems are beneficial to the environment in that they reduce greenhouse gas emissions, which contribute to climate change, which contributes to water scarcity and degradation — a damaging cycle.
Energy efficiency in wastewater treatment operations is certainly the wave of the future. Because of increased loads and decreased budgets, municipal wastewater treatment plants are finding it necessary to implement cost-effective solutions in order to operate sustainably. Implementing an energy audit and incorporating energy efficient strategies into day-to-day operations at wastewater treatment facilities will provide significant economic and environmental benefits, and provide a safe, clean future for generations to come.
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