Tag: energy efficiency

3 Sustainable Clean Water Ideas for a Warming World

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.

ThermometerThe 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.

Primordial-bacteriaWastewater 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-plant
Shawaikh Reverse Osmosis (RO) desalination plant in Saudi Arabia.

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.

fog-nets
Super-sized fog nets can capture moisture in coastal or mountainous areas to convert fog into safe drinking water.

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.

AWG Towers
Large scale Atmosphere Water Generators can be installed on roof tops.

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.

Our future depends on it!

State Revolving Fund Loan Program

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.

Water Main ReplacementFinancing 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.

In addition, Housing Choice Communities will receive a discount on their SRF interest rate of not less than 1.5%.

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.

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We Can Help

For more information on the MassDEP State Revolving Fund and assistance preparing a PEF contact us.

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The Importance of Incorporating Sustainability and Efficiency into Modern Water Treatment

sustainability conceptMunicipal water treatment and distribution requires an exorbitant amount of resources, wreaking havoc on the environment and on budgets. And it’s getting worse. Over the past several years, operating costs have consistently been on the rise, while municipal budgets continue to shrink. In addition, regulatory requirements are increasing, forcing municipalities to upgrade treatment processes ahead of schedule. These changes result in limited unsustainable systems and utilities scrambling to find ways to manage their insufficient operational budgets while maintaining levels of service. The good news is that low-cost initiatives exist that can provide quick and significant cost and environmental savings and increase system sustainability.

When incorporating sustainability into water systems, utilities consistently rank capital cost, life-cycle costs, and service lifetime as the top three considerations, while climate change and habitat protection are the lowest ranked factors. These statistics highlight the extreme fiscal challenges facing utilities today. While environmental factors are certainly important, water systems simply do not have the luxury to place them above financial concerns, as budgets are reaching a critical juncture. In short, cost drives decision-making. Fortunately, energy efficiency and sustainability result in a healthier environment, even when implemented primarily for cost-savings.

wayland water treatment plant
Tata & Howard completed a water audit for the Town of Wayland, MA.

There are many technologies and practices that water systems employ to increase sustainability and energy efficiency, the most common of which is reducing non-revenue water (NRW). NRW includes real losses, the majority of which is the result of leaks in the distribution system. In fact, the United States loses about seven billion gallons of water every day to leaking pipes — enough to supply the nation’s ten largest cities with water — and this lost water puts a strain on supply, budgets, and the environment. Reducing NRW is most easily accomplished with a water audit, which helps water systems identify the causes and true costs of water loss, and develop strategies to reduce water loss and recapture lost revenue. Water audits are often the most cost-effective and efficient solution to increasing demand, and the return on investment of a water audit is typically less than one year. Effective water loss control programs reduce the need for facility upgrades and expansions as well as the need to find additional sources, while the recovered water helps systems to generate revenue and meet demand. In addition, an effective water loss control program protects public health by identifying the leaks from which disease‐causing pathogens can enter the system.

Other technologies and practices include educating customers on water conservation, source water protection planning, automated meter reading, and trenchless pipe repair, as well as energy audits. When water utilities decide to integrate sustainability and efficiency into their operations and infrastructure, the best place to start is with water loss. Water loss reduction initiatives tend to have a quick return on investment while providing significant cost and environmental savings. Once the effects of these savings are realized, implementing other green initiatives becomes more appealing and justifiable to management and water boards.

long pond water treatment plant
The newly completed 8.0 mgd DAF Long Pond Water Treatment Plant incorporates several energy efficiency and sustainability features.

For new treatment plants, incorporating sustainability and efficiency features into the initial design allows the plant to function at a superior efficiency level right from the start. As an example, Tata & Howard provided design, permitting, and construction services for the new Dissolved Air Flotation (DAF) Long Pond Water Treatment Plant in Falmouth, MA. The project consisted of the construction of a new 8.0 mgd water treatment plant (WTP) for the existing Long Pond surface water supply.  The existing Long Pond Pump Station, constructed in the 1890s, operated under a Filtration Waiver issued by the Massachusetts Department of Environmental Protection and did not include filtration processes to remove algae, organics, or particulates from the water.  The new WTP provides the Town with several key benefits:

  • Meets the current regulatory requirements of the Long Term 2 Enhanced Surface Water Treatment Rule;
  • Reduces disinfection by-products and organics;
  • Removes pathogens, taste, odor, and algae/algae toxins;
  • Produces stable water quality;
  • Provides the flexibility to meet uncertain future regulatory and water quality challenges.

In addition to providing a solution to the water challenges faced by the Town of Falmouth, the Long Pond WTP also provided more sustainable and efficient operations, saving the Town money while also protecting the environment. Some of these initiatives included the following:

  • Recycling spent backwash water to head of plant and back into the treatment process, after it passes through a plate settler to remove solids;
  • Recycling laboratory analyzer and filter influent piping gallery analyzer discharges back into the treatment process;
  • Using filter-to-waste water after a filter backwash sequence as supply water for the next backwash, instead of using finished water for backwashing;
  • Discharging cleaner supernatant water off the top of the lined lagoons to an unlined infiltration lagoon and back into the ground to minimize residuals;
  • Use of local/native plants for landscaping, including an irrigation system using collected rainwater from roof drainage;
  • Interior and exterior LED lighting fixtures; and
  • Variable Frequency Drives (VFDs) on HVAC equipment and process equipment motors.

sustainability conceptEfficiency and sustainability are no longer considered luxuries for water systems. Rather, incorporating green initiatives into infrastructure design and operational standards has become crucial to the future sustainability of water systems. And while utilities today value cost-effectiveness over environmentalism due to the criticality of their budgets, there will likely be a shift in thinking as these systems ease the burden of their unsustainable operational costs through effective practices such as efficiency and water loss reduction.

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Shared WW Treatment Facility Improvements Whitepaper

wastewater treatment facility improvements whitepaper

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.

The Importance of Energy Efficiency in Water and Wastewater Treatment – Case Studies

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.

MBR membrane installation

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.

Case Studies

Canaan, VT and Stewartstown, NH Shared Wastewater Treatment Plant Upgrades

The new Canaan, VT Stewartstown, NH shared wastewater treatment plant

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.

Solar mixers for lagoons

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.

wastewater treatment facility improvements whitepaper
Click above to download the complete whitepaper on this important project.

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.

The project received an Engineering Excellence Merit Award from the American Council of Engineering Company’s Vermont Chapter in 2017.

Shrewsbury, MA Home Farm Water Treatment Plant Design

Excavation for the new 7.0 mgd Home Farm Water Treatment Plant began in July 2017

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.

Download the complete whitepaper on the Mangazur™ Home Farms Water Treatment Plant here.

Flagstaff, AZ Water Reclamation Facility Upgrades

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.

Wastewater treatment plant in Flagstaff, AZ

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.

Download a case study on the energy efficiency project in Flagstaff, AZ here.

In Conclusion

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.

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The Water-Energy Nexus: A Vicious Cycle

Water and energy are the two most fundamental ingredients of modern civilization. The water-energy nexus is the relationship between how much water is evaporated to generate and transmit energy, and how much energy it takes to collect, clean, move, store, and dispose of water. Without water, people die. Without energy, we cannot grow food, run computers, or power homes, schools, or offices. As the world’s population grows in number and affluence, the demands for both resources are increasing faster than ever.

The Water-Energy Connection

Energy production is the second largest consumer of water, the first being agriculture. Electric power plants that are fueled by oil, coal, natural gas, or nuclear power require exorbitant amounts of water to cool them, and hydropower plants require water to create energy. Likewise, a significant amount of energy is used in the pumping, treatment, and distribution of water, as well as in the collection, treatment, and disposal of wastewater. In addition, the extraction of fossil fuels used for heating and cooling homes also requires vast amounts of water. Clearly, the relationship between energy and water is inexorably intertwined.

nuclear_cooling_towers
Byron Nuclear Generating Station, located near the small city of Byron, Illinois, has been subject to some controversy with respect to a lawsuit in 1981 with concerns over tritium contamination in groundwater. Tritium contamination at Byron and other Illinois nuclear power plants led the state of Illinois to pass legislation requiring plants to report such contamination to the state within 24 hours.

As the population and affluence of the nation continues to increase, so does the demand for both water and energy. Also, climate change has been responsible for increasingly frequent water shortages, requiring communities to find water elsewhere – which requires even more energy. Pumping water from distant areas or glacial icecaps, desalinating ocean water, and highly treating wastewater to potable standards all require exorbitant amounts of energy. Previously, these methods for obtaining potable water were ignored due to their high energy usage. But as water shortages and drought continue to plague the nation, even affecting the historically wet northeast part of the country, more creative ways of meeting the nation’s demand for water must be innovated and implemented.

Likewise, fossil fuels such as oil and gas are being withdrawn at an unsustainable rate, and supplies are dwindling. As these inexpensive energy sources are depleted, our dependence on alternate, more water-intensive sources of energy increases. This endless cycle of water-energy usage has the potential to spiral out of control, and the only way to make a real and lasting change is for policy makers, businesses, and communities to join forces in the planning, management, and conservation of resources and in the innovation of sustainable solutions.

Planning and Management

Many U.S. aquifers span several states
Many U.S. aquifers span several states; map courtesy of U.S. Geological Survey

One of the key factors to a sustainable future is communication. In the United States, there is little overlap in governmental agencies when it comes to water and energy. The Department of Energy has been an entity since 1977, and yet our nation still does not have an agency dedicated solely to water planning. While the EPA oversees water quality and the U.S. Geological Survey collects and interprets data related to supply, there is no single federal agency that ensures the effective use of water. In fact, much of the onus of water management lies not with the federal government, but with state agencies and municipalities. This can prove problematic when aquifers or watersheds span multiple cities and town, or even states. A logical approach to water management would be a federal agency that oversees all aspects of water management, from quality to supply to usage. In this way, federal energy and water agencies could collaborate to help forge a sustainable future. For example, when a new power plant is proposed, discussions should take place on not only the siting and permitting of the new facility, but also the effect on air and water quality, as well as water usage and potential for scarcity. In this way, more focused attention on the usage and effects of both energy and water will lead to more holistic — and sustainable — installations.

Value and Conservation

One of the greatest concerns of the modern day American is the risk of running out of inexpensive oil. The cost of oil pushed gasoline prices to $4.48 per gallon in 2008, and was partially responsible for the great recession of 2009. Realizing that the end of cheap oil could spell economic disaster, many people have begun to look at alternate heating sources for their homes, and alternate means to power their vehicles, such as biofuels or electricity. But how much more disastrous would it be to run out of cheap water? Peak oil would admittedly cause economic difficulty as well as some amount of human hardship, but peak water has the potential to cause far direr consequences. Millions of people globally already die from lack of access to an improved water source, and peak water would increase that number exponentially.

Drip irrigation is far more water efficient than spraying
Drip irrigation is far more water efficient than spraying

It is critical that the value of water be realized if we are to start making real changes. Gasoline prices are currently around $2.20 per gallon, while a gallon of municipal water costs less than one penny. And yet, we can live without gasoline – we cannot live without water. As society begins to understand that procuring, treating, and distributing water is an expensive task and that supplies are limited, we can innovate technologies that reduce the amount of freshwater that we use. For example, in the western part of the country, the Ogallala aquifer is being depleted at a rate far higher than it is being replenished, and irrigation accounts for 94% of the groundwater withdrawals in that area. Switching to a more water efficient irrigation process such as drip irrigation rather than spray would save a significant amount of water. Also, utilizing reclaimed water for crop irrigation, cooling power plants, and industry would greatly reduce our groundwater withdrawals. Even at the residential level, conservation is important. Community outreach programs and educational materials can be used to teach residents how they can save water in their homes and businesses. Simple, low-cost initiatives such as mowing grass to a higher level, utilizing rain barrels, and planting native trees and plants can have a huge impact when implemented on a large scale.

And let’s not forget about energy. Energy conservation is directly linked to water conservation, and it is critical that saving energy happen at both the industrial and residential levels. All businesses should examine their energy efficiency and implement energy-saving initiatives. And businesses that utilize a lot of water, such as hospitals and hotels, should conduct water audits to examine and modify their water usage. Wastewater treatment should include technologies that create energy from waste, such as anaerobic digestion, in order to offset the energy used in treatment processes. Likewise, homeowners should be educated on the importance of saving energy. Utilizing energy efficient lighting, turning the heat down by a degree or two, and unplugging appliances, computers, and chargers that are not in use are just a few of the ways that the individual American can save energy. In addition, heating residential water uses a significant amount of energy, while solar water heating is a simple technology that is as inexpensive as it is effective and efficient. Unfortunately, it has not received any type of federal backing or media attention, and remains relatively unknown. Both education and policy are critical to the widespread implementation of energy saving initiatives.

In Conclusion

Energy and water are both precious resources that are critical to our health, our economy, and our way of life — and they are inextricably linked. Of the utmost importance is that we value water. Until water has a realistic price on it, as energy does, it will be seen as a resource that can be used and wasted at free will. Only with accurate pricing can the link between water and energy be made apparent to consumers, and that conserving water conserves energy, and vice versa. Likewise, with true pricing consumers would see that as the price of water increases, so does the price of energy, and that as the price of energy increases, so does the price of water. Feeling the effects in our pockets would increase the appearance of value, act as a strong motivator to more aggressive conservation, and would prompt the innovation and implementation of more efficient, green solutions.

Energy Efficiency in Wastewater Treatment = Big Savings for Municipalities

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.

VoltsThe 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

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.

fluorescent light bulbHeating, 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.

Operating Strategies

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 Management

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.

Operational Management

Procedure ListWhile 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

Digester eggs at the Deer Island Wastewater Treatment Plant operated by the Massachusetts Water Resources Authority (MWRA) in Massachusetts
Digester eggs at the Deer Island Wastewater Treatment Plant operated by the Massachusetts Water Resources Authority (MWRA) in Massachusetts

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.

In Conclusion

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.

The Criticality of Energy Efficiency for Water and Wastewater Utilities

electricity meterMunicipal water and wastewater services require electricity, and lots of it. Drinking water and wastewater systems in the United States account for 3-4% of our nation’s total energy usage and add over 45 million tons of greenhouse gases to our environment each year. High energy costs for water and wastewater utilities are straining municipal budgets and creating unsustainable operating costs, and with prices already on the rise due to increasing regulations and demand, passing energy costs on to consumers simply isn’t a viable option. Drinking water and wastewater treatment plants account for 30-40% of the total energy consumed by municipal governments, making them the single largest energy consumers in the municipal sector. Add to that the fact that energy currently accounts for an average of 40% of operational costs for drinking water systems and is expected to increase to 60% within the next 15 years, and it becomes clear that energy efficiency for water and wastewater utilities is no longer a choice – it’s a necessity.

But it’s not all doom and gloom. Energy costs for water and wastewater utilities are indeed significant, but they also represent the largest controllable cost of providing water and wastewater services. Studies have estimated that 15-30% energy savings is readily achievable through cost-effective efficiency measures in water and wastewater plants, and that utilities can realize significant financial returns with a payback period from only a few months to about five years.

lightbulb water Very often, utilities can save substantially by increasing the efficiency of pumps and aeration equipment at water and wastewater treatment plants. In addition, operational changes such as proactively shifting energy usage away from peak demand times where electricity is most expensive, or generating electricity and heat from biogas, can greatly reduce energy usage. Water and wastewater utilities are not typically designed and operated with energy efficiency as a primary objective, as more pressing concerns such as regulatory requirements, capital expenditure, reliability, and securing funding typically take precedence. However, it is important not to overlook these systems when communities fund energy improvement projects, as significant energy and monetary savings can be realized through operational changes and capital improvement projects. And these savings make a big difference. Even a 10% energy reduction in our nation’s drinking water and wastewater systems would save about $400 million and five billion kWh annually, greatly reducing both the financial burden currently plaguing water and wastewater utilities as well as our impact on the environment.

But where to start? The first step towards making informed decisions that result in the highest return on investment (ROI) in the shortest amount of time is an energy audit. Since 2008, EPA has been actively working with water and wastewater utilities to help them become more efficient and to reduce operational costs, and one of the key steps in their process is an energy audit. A quality water and/or wastewater energy audit should focus on energy efficient equipment replacement, operational modifications, and process control that will lead to improved efficiency and cost savings with the shortest possible payback period, and includes processes such as conducting on-site observations, testing existing systems and equipment, monitoring power usage and costs, and developing strategies to limit demand charges.

Kachina, Arizona
Kachina, Arizona

As an example, Tata & Howard conducted an energy audit on the water production assets and distribution system of the Kachina Village Improvement District (KVID) in Arizona. During the course of the study, the well pumps and booster pumps were evaluated relative to their efficiency while the operational practices of the distribution system were reviewed. The results of the study indicated that the pump efficiencies ranged from 27% to 60%, and it was recommended that the KVID replace several low performing pumps. The cost of the upgrades was $136,000 and the project would be eligible for a $20,000 rebate from Arizona Public Service (APS). With the upgrades, KVID would save approximately $23,000 in annual power costs, resulting in a projected ten-year savings of $114,000 and a payback period of five years.

For new construction, it is imperative to choose a design firm with clear experience in designing energy efficient projects, as the design phase is the absolute best time to think about energy efficiency as well as renewable energy options. A plant that is designed with energy efficiency and renewable energy from the beginning has the potential to actually produce more energy than it uses.

Allocating the resources and time to conduct an energy audit and implement the required capital improvements and operational changes can produce significant benefits. Energy audits can pinpoint the most energy-consuming equipment, detect issues with aging equipment, and expose operational issues, as well as determine which upgrades would result in the best ROI. The result is a well-defined, defendable plan of action that will result in optimal energy savings.

www.epa.gov
www.esmap.org
www.nrel.gov
www.ase.org
www.mass.gov

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