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April 18, 2013

New On-Site Water Generation Study
Water Energy - on-site water generation, recycled water, wastewater treatment, water distribution, water efficiency, water energy, water loss control - California Sustainability Alliance

 

California water supplies are stressed as a result of decreasing supply and increasing demand.  While conservation and efficiency are the most cost-effective solutions, they may not completely solve the problem. Consequently, California water planners are considering multiple alternate water supply options including:

  • Desalination
  • Brackish water treatment
  • Rainwater harvesting (storm water capture)
  • Recycled water

Of these, water recycling is the only option that is applicable across the entire state and which can produce a relatively consistent resource regardless of the season or weather.  Wherever there is a wastewater treatment plant there is an opportunity to generate a local supply of recycled water.

Indeed, generating recycled water is not a challenge, distributing it is.  A major barrier to implementing a successful regional recycled water system is the cost of distribution pipelines. Typically a network of distribution pipelines and pump stations is needed to connect existing municipal water reclamation plants to potential recycled water customers.  Constructing these distribution systems can be expensive ($2-4 million per mile), especially in heavily developed areas such as Southern California. As a result, excess recycled water supply generated by large centralized plants cannot always be used cost-effectively. The Alliance’s 2008 report on recycled water shows that enough existing recycled water supply to meet all of Southern California’s projected increase in water use through 2030 is currently being released to streams and the ocean without benefit.

Recycled water can be implemented on a smaller scale; generating water in the same location as its demand eliminates the need for expensive distribution systems. Additionally, water supply and conveyance accounts for the majority of energy use by the state’s water infrastructure - imported water is among the most energy intensive (especially in Southern California).  On-site water generation has the potential to not only conserve water also save embedded energy in water.

To better understand the opportunity for on-site water generation, the Alliance has released a new study entitled On-Site Water Generation: An Analysis of Options and Case Study .  The study documents the characteristics of on-site water generation systems and also conducts a detailed cost benefit analysis for a representative case study on the City of Huntington Beach, California.Specifically the studyexplores:

  • Types of technologies available to provide on-site water generation
  • Costs and benefit analysis of the on-site water generation options
  • Primary market barriers to technology adoption.

Key study conclusions include:

  • On-site recycled water systems can supply water at lower energy intensity than imported water and desalination in Southern California. 
  • On-site Recycled water systems are most cost-effective in larger capacities. 
  • On-site water recycling relies on a consistent supply of wastewater and thus can provide more water than rainwater harvesting in Southern California

The study also discusses a number of recommendations for California policy-makers to stimulate the production and use of on-site water generation. Download  the full report for more details.

October 27, 2012

Employing Public Engagement for the Successful Water Reuse Project
Water Energy - public engagement, recycled water, water efficiency - California Sustainability Alliance

Water reuse projects have garnered concern and even opposition from community members and the public. While based on legitimate concerns, public aversion to recycled water is often fueled by a lack of knowledge resulting in an inflated perception of risk. However, active public outreach and participation can effectively shift public opinion. The EPA’s recently released 2012 Guidelines for Water Reuse dedicates an entire chapter to the issue of public outreach. The report (specifically Chapter 8) draws conclusions and recommendations from recent studies on public perception of recycled water and steps towards effective engagement. This post summarizes some of those key findings.

The last decade has seen an increase in public dialogue and increased knowledge about water reuse. A corresponding shift in public opinion was shown in a study conducted by San Diego County Water Authority. Conducted in 2004 and 2011, the study found people who “strongly oppose” recycled water dropped from 45% to 11% while those who “strongly favor” it increased from 12% to 34%.

Public engagement should be framed as a collaborative problem-solving effort that focuses on the benefits of a water reuse program. When the public understands the problem at hand (e.g. water scarcity and drought) and the benefits of implementing recycled water, they can better perceive an improvement in the state of affairs. Public participation should begin with an understanding of why recycled water is needed, the available options for reuse, and the potential concerns.

When presenting information on water reuse, a balance between technical detail and easily understood information is important. This creates validity while effectively relaying information. In the same way, the terminology used to present reuse projects can greatly impact the public’s reception. Some of the terms used in the industry are often not well understood or well received by the general public. The EPA Guidelines show that terms such as “Water that is purer than drinking water” or “Very pure water” were reassuring to over 60% of respondents while less than 20% found “NEWater,” “Recycled water,” and “Reclaimed water” reassuring. Based on their findings, the EPA offers recommendations for public outreach terminology and methods. These include:

  • Emphasis on the purity of recycled water
  • Focus on future uses rather than the source by avoiding the prefix “re”
  • Offer analogies and water reuse in the context of the water cycle
  • Make understanding accessible and avoid technical terms

Public involvement generally begins with direct stakeholder engagement, particularly those who will be most impacted. This can involve activities such as surveys, community events, public meetings, presentations, and workshops. While direct contact and activity is important with key stakeholders, media outreach can play a significant role in shaping the general public perception and increase the flow of information and dialogue among constituencies.

Several water agencies serve as prime examples of successful public engagement and implementation of recycled water projects. Orange County Water District (OCWD) was particularly successful in engaging the public through its diversity of outreach for its Groundwater Replenishment System. OCWD also overcame reuse misconception to garner public support for an indirect potable reuse project. Read more about their success here. San Diego County Water Authority facilitates successful public communication by conducting surveys to measure knowledge and opinions of water issues and then sharing the results with the public.

For more details and advice on successful public engagement, check out Chapter 8 of the EPA’s 2012 Guidelines for Water Reuse.

March 29, 2012

Sustainability Innovations in the Wastewater Industry
Water Energy - water efficiency, water energy - Amul Sathe
Today’s technology innovators view wastewater as a valuable resource.

In 2010, I wrote about Imagine H2O (an incubator hosting prize competitions for water innovations) as they launched their second annual prize competition focused on the water-energy nexus. Recently, I attended Imagine H2O’s 3rd Annual Water Entrepreneurs Showcase at which the organization announced the winners of their 2011 prize competition for innovations in the wastewater industry.

This year’s competition attracted 50 startups, from which nine finalists were selected.  The competition was split into two categories, a pre-revenue track and an early revenue track.  Bilexys won the Pre-Revenue Track for its technology that converts wastewater into chemicals which can then be reused in the treatment process.  New Sky Energy won the Early Revenue Track for its technology that combines CO2 and industrial wastewater to extract usable chemicals from the wastewater stream. Additionally, Nexus eWater and Tusaar, Inc. were named runners up in the Pre-Revenue Track— Nexus eWater for its technology that converts residential gray water into near-potable water and recycles its energy for hot water heating, and Tusaar for development of a low-cost technology to remove heavy-metal contaminants from wastewater effluent.

Imagine H2O’s event heralds a turning point in the wastewater industry.  In the past, wastewater treatment was a service and technology field that was often an afterthought.  I found it especially refreshing that three of the four winners and runners up viewed wastewater treatment as an opportunity, not a necessary burden.  By viewing wastewater effluent as a resource (from which chemicals can be manufactured, heat can be recovered, and useable water be produced), the winning teams are both creating economic value and increasing sustainability in the water sector.  These innovations can save embedded energy by reducing energy use associated with water supply and chemical production.  Meanwhile, the remaining finalists in the competition focused on reducing the cost and energy requirements of treating wastewater and producing recycled water, both noble causes.

During the acceptance speeches, one winning team explained they are driven by the idea that “water is one of the few un-substitutable resources on this planet”.  As water-stressed regions (including California) continue to see decreases in supply and increases in costs, it will become apparent that wastewater effluent is no longer a waste but instead a resource and path to sustainability.

Imagine H2O places winners in an accelerator program which provides accounting and financial services; introductions to beta customers, financiers, and market partners; assistance in securing lab and/or office space; and publicity.  If Imagine H2O’s efforts are successful, we may never look at a wastewater treatment plant the same again.

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February 10, 2012

A look at the National Research Council Report: Water Reuse Potential for Expanding the Nation’s Water Supply
Water Energy - water efficiency, water energy - California Sustainability Alliance
12 billion gallons of municipal wastewater effluent is discharged into the ocean each day.

Is it possible to meet our future water supply needs through the reuse of municipal wastewater? This is a question the National Research Council (NRC) had in mind when the Assessment of Water Reuse Committee was formed by the NRC’s Water Science and Technology Board. Since wastewater is discharged into the environment in significantly large quantities—approximately 12 billion gallons of municipal wastewater is discharged to an ocean or estuary each day—the committee critically assessed the practicality of reusing water to meet future supply needs by analyzing technical, economical, institutional and social issues associated with water reuse.

This isn’t a new idea, as water reuse is a very common practice within the United States for irrigation and non-potable applications; however, as the NRC’s report states, using reclaimed water to augment potable supplies has significant potential for helping meet future needs. The EPA previously estimated the extent of water reuse in the United States; as of 2002 Florida was reusing the largest quantities followed by California, Texas and Arizona.  Over 50% of the reclaimed water in Florida and California was used for irrigation. 

So then the question is begged, how will people react to drinking recycled wastewater?  Although it sounds unsanitary, with the right wastewater reclamation technology and monitoring systems, the potable reuse of highly treated reclaimed water becomes worthy of consideration.  The committee found that the current technology is very advanced with room for improvements but no real limitations. To help address public concerns about safety of reuse and the effects on human health and the environment, the committee proposed 14 priority research areas within two categories: health, social and environmental issues; and performance and quality assurance.

Several advanced treatment facilities in California and throughout the world provide examples of successfully managed systems that are expanding local water supplies.  In Southern California, Orange County Water District’s Groundwater Replenishment System recycles wastewater using advance treatment processes.  Half of the treated wastewater (about 35 million gallons a day) is used to recharge the local groundwater basin which supplies potable water to the county.  Elsewhere, Singapore’s NEWater system recycles wastewater that subsequently meets 30% of the nation’s water demand.  Currently only a small percentage of NEWater is being used to augment potable supplies.

As the world’s water supply decreases and as population increases, the need for water reuse becomes even more vital—especially for water-limited regions.  Although reuse alone will not address the nation’s water challenges, municipal wastewater reuse has the ability to significantly increase the world’s water resources.

Find out more by reading the full report here. 

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February 2, 2011

Ocean Friendly Gardens
Water Energy - energy efficiency, water efficiency, water energy - Amul Sathe
Ocean friendly gardens are a more sustainable gardening practice reducing outdoor water use.

Approximately half of all residential water use in California is for outdoor purposes—and, of that, the majority is used for watering lawns and gardens.  In total approximately 1,300,000 acre feet of water is used for watering lawns and gardens; enough to cover the entire County of Los Angeles with six inches of water.  Producing, transporting, treating and delivering that water requires a significant amount of energy.  In a state that had below-normal precipitation in 8 of the last 10 years (including a 3-year drought), can using such significant amounts of water (and related energy) in this manner be considered sustainable?

New technologies and approaches allow for greater efficiency of outdoor irrigation.  Options range from high efficiency nozzle replacements on sprinklers to weather sensing irrigation controllers.   Meanwhile, some have suggested outright replacement of grass with synthetic turf.  However, one option stands out for not only reducing water use but also adding to the property values of California homes, while at the same time reducing ocean pollution: ocean friendly gardens (sometimes referred to as xeriscaping).

Ocean friendly gardens utilize drought resistant California native plants in plots that are designed to capture home stormwater runoff.  They require little, if any, irrigation.  Water is supplied to the gardens by rerouting downspouts that would normally send rainwater to the streets or sewer systems—water that would otherwise wash pollutants such as fertilizers, pesticides and oil into California’s rivers and ultimately pollute our oceans and beaches.  Ocean friendly gardens are specially designed to retain the influx of storm water and achieve near-zero runoff.  Contours and dry creek beds built into the landscapes retain water, allowing it to percolate into the ground.

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