Extraordinary Measures Taken to Diversify Sustainable Water Supplies in Western Cities

 

The Mayors Water Council convened their spring 2017 meeting in Santa Barbara, hosted by Mayor Helene Schneider on April 13-14, 2017. Mayor and Water Council Co-Chair Jill Techel led a diverse group of mayors, local and state elected officials and their representatives, staff from regional water control districts and national experts from industry in a discussion of western water supply challenges and national water infrastructure investment and financing.

Western Cities Water Supply Challenges

Amid the concerns over drought, California local governments generally have a positive story to tell about investment in public water and sewer; and that is important because it affects the daily lives of some 38 to 39 million state residents, local commercial and industrial businesses, and public institutions. It is a barometer of California’s local government commitment to ensuring safe drinking water and protecting and improving water quality. Local governments in California invested $10.9 billion in 2000 and doubled that investment to $21.5 billion by 2013. The current Census estimate for 2014 is $22.1 billion- another increase of 2.56% when the national average for year over year growth in American cities was 2.2%.

Safe drinking water and protection of water quality are costly activities for local government, and strong local balance sheets and resources are a pre-requisite for investment. Here too, like investment in water and sewer, California local government finances tell a positive story. Total local government revenues and own-source revenue (property, income and sales tax; and fees and charges for services) have doubled from 2000 to 2014 while population has increased roughly 15%. Public water and sewer are financed with a combination of debt and ‘fee for services’ revenues from customers (households/rate payers). Fees for water and sewer services are usually a component of own source revenue. The latest local government Census data in California indicates that own source revenue increased 88% from 2000 to 2014, and local investment in public water and sewer has risen along with and above the national average at 102%. Additionally, the ratio of long-term debt is flat or slightly declining: the ratio of long-term debt to own source revenue was 1.7 in 2000, 2.06 in 2013 and 2.03 in 2014.

Strong cities with strong balance sheets and creditworthiness will be required for cities in the state to continue to provide water and sewer services that are safe, adequate and affordable. Even with favorable resources, investment in sewer infrastructure will be a major challenge for California cities to comply with water quality standards and continue to provide uninterrupted services.

The water supply component of annual investment, double that of sewer investment, is spread over the state in cities from north to south, but transfers of water north to south, and reliance on traditional supplies has proven to be risky in the last and very recent drought. Cities introduce resiliency by diversifying water supply sources. Interestingly, treated wastewater discharges often leave the city on the downstream flow of a river, but now cities are eyeing that flow as a possible new source. Similarly, storm waters usually run off into lakes, streams, and oceans; but now cities see that runoff as a new source of supply. Water recycling for both potable and non-potable uses are becoming common practices. Mayors and national experts participating in the Santa Barbara conference discussed a variety of city and regional projects they are investing heavily in, and the information is emerging on the cost of these various diversification options compared to traditional single-source treatment costs. The experts caution, however, that proliferation of recycling and reuse will likely face federal regulatory impediments with the lack of policy, rules or guidance.

A variety of local solution sets and practices were discussed and outlined below.

City of Santa Barbara: Host City Mayor Schneider reviewed the drought program put in place in Santa Barbara. Recently, California Governor Jerry Brown officially ended drought consumption restrictions, but Mayor Schneider stated that Santa Barbara will continue with their conservation program for the foreseeable future. The program is guided by a local strategy of diversity and resilience. The city uses a 3-Year Water Supply Strategy and measures performance with a stress test:

  • Assume drought conditions
  • Make desalination operational
  • Restore groundwater with recharge
  • Return borrowed water
  • Maintain and build reservoir storage in Cachuma Lake

The column chart below illustrates how Santa Barbara plans to shift from 5 supply sources in 2012 to 8 sources by 2019. Desalination is anticipated to become a major supply source. Groundwater recharge and water recycling are part of the plan. Extraordinary levels of conservation efforts play a major role in 2017 to 2019, despite the official end of the drought. The expanded sources will not eliminate the need for imported supply, but it can provide more future certainty for the city and its residents.

Santa Barbara Water Supply Sources

City of Turlock: Mayor Gary Soiseth gave an update on the North Valley Regional Recycled Water Program Partnership (NVRRWP) in the Central Valley of California- an economic hub for agricultural and dairy production with limited water supply. The regional Partnership includes the City of Modesto, the City of Turlock, and Del Puerto Water District (DPWD) as primary partners. The City of Ceres and Stanislaus County are also signatories to the program.

The San Joaquin River is currently a water supply source but is stressed due to the drought. Currently, Turlock and Modesto treat their wastewater to recycled quality, but discharge it to the San Joaquin River and it leaves the region. The NVRRWP will allow Turlock and Modesto to send its treated wastewater to the Del Puerto Water District via a direct pipeline to the Delta-Mendota Canal. DPWD will distribute as much as 30,600 acre feet to agricultural customers in the service area by 2018, and more over time.

The Partnership is a vehicle for treated wastewater to be recycled for industrial consumption, but Mayor Soiseth emphasized it was established to create multiple economic and environmental benefits:

  • Provide a regional solution for a local water supply crisis
  • Make recycled water available for agricultural irrigation and potential wildlife refuges
  • Allow Cities to eliminate discharge to the San Joaquin River
  • Provide long-term, reliable water supplies to DPWD to mitigate on-going and severe contractual water supply shortages
  • Reduce reliance on Delta conveyance and groundwater pumping to meet unmet water supply needs

Mayor Soiseth stated that the pumps and pipeline(s) have an estimated $98 million capital cost. Project financing estimates anticipate a combination of 30-year bonds, and both 30-year and 20-year State Revolving Fund Loans. Depending on potential grants and traditional financing, Soiseth said that the anticipated cost per acre foot ranges from $180-$320.

City of Los Angeles: Adel Hagekhalil, Assistant Director of Sanitation, reported on LA’s comprehensive efforts to align “One Water” goals in city practice. While complex in scope and logistically challenging, LA may be shaping the new standard in city water/wastewater planning with wastewater recycling and stormwater management being the key to ensuring a diverse supply for the city. Hagekhalil stated that LA treats 350,000 gallons of wastewater per day and most of the effluent goes to the ocean. Similarly, he stated that every ½ inch rainfall generates 3-4 billion gallons of runoff to the ocean. Since the city relies on imported water it only makes sense to find ways to store and use the treated wastewater and storm runoff.

The city went into planning mode and came up with a diversification plan that would help ensure future supplies. Treated wastewater is planned to be recycled as non-potable reuse, and as indirect potable reuse; storm water will be captured; consumption will continue to be curbed by conservation measures; and, the city will enhance replenishment of the San Fernando Groundwater Basin at the Hansen and the Pacoima Spreading Grounds by conveying treated effluent to an advance purification plant and then recharge in the ground basin.

Sustainability pLAn Goal:
Meet 50% Local Water Supply

854,000 Acre Feet/Year (AFY)

Cadiz Valley Water Conservation, Recovery & Storage Project: Cadiz Inc. CEO Scott Slater described a private investment in the Cadiz Valley (halfway from LA to Las Vegas) that would capture and store 50,000 acre feet of water from mountain snow-pack that ordinarily would evaporate at a high rate. The project takes advantage of a significant aquifer that has been fed from snow melt minus the evaporated portion. Slater described the storage strategy for consumption and conservation. He stated that the water supply could continue supporting existing farming operations in the Valley and up to 400,000 people in southern California. A 43- mile pipeline is planned to fit in the railroad right of way to distribute water. (1 acre foot of water equals 325,850.9 liquid gallons).

Slater reported that there is no public funding involved in the project. The private investment is estimated to create 5,900 jobs and add $878 million in construction stimulus. He also stated that the California environmental review concluded there are no environmental impacts associated with the project.

Cadiz Water Conservation, Recovery & Storage Schematic

Jonathan Loveland, Global Practice Leader, Alternative Water Supply, Black & Veatch:

Loveland briefed mayors on the trends in supply diversification, its public benefits, and the major challenges local governments face in augmenting existing supplies. “The benefits”, said Loveland, “allows for growth, increases certainty and resiliency”, but he went on, “it comes at a premium”. And then he told the story of 3 local governments that were successful in their efforts to diversify water supply for a variety of reasons.

Black & Veatch surveys hundreds of municipal customers each year to learn their thinking on a host of water and energy issues. The main drivers for seeking alternative water supplies are clearly drought (~ 60%); and 33.8% stated resilience as a reason. The two reasons are not incompatible. The single most important challenge to pursuing alternative supplies is cost/financial (60%).

Loveland provided summaries of three locales:

  • Loudon County, VA:

One of the fastest growing regions in the country, Loudon relied on 20 million gallons a day (mgd) from a surface water source in 2000. Nearly half of supplies in 2015 came from an alternative surface water source, and the traditional surface source is augmented with conservation and recycling. The 2070 demand estimate is 70 mgd, and conservation and recycling will need to maintain or grow share.

  • Central Florida Initiative:

Like Loudon, Central Florida is expanding capacity to accommodate population growth; here, it is estimated to be 50% in 2030. The historic water source is groundwater and some untapped surface water. The strategy adopted in the initiative is to diversify one-third by 2030 by a combination of conservation and recycling. Groundwater will continue to be a staple of the mix, and some surface water will play a role.

  • San Diego County:

San Diego County performed an amazing transformation in water supply diversification from 1991 to 2017. Conservation in 1991 involved saving 875-acre feet, and the 2017 goal is 100,000-acre feet. The diversity introduced is 24K-acre feet of recycled water; 6K acre feet of recovered brackish groundwater; and, 56K acre feet from seawater desalination. Loveland then provides a chart of the cost for each source included in the San Diego case.

Loveland presented the chart below to illustrate the range in cost for the various levels of treatment involved. So, the treatment of wastewater effluent to drinking water quality may be very expensive; and so is getting the salts out of brackish groundwater and seawater. The chart confirms that groundwater is still a bargain. Surface water can also range to the low cost. What is striking, however, is that the ranges overlap, substantially, for surface water, recycled water and seawater reverse osmosis (SWRO).

Comparative Treatment Costs

Type

Treatment

Cost

($/AF)

Cost

($/1000gal)

Groundwater None or Filtration + RO

200 – 500

0.62 – 1.53

Surface Water Pumping + Aqueduct + Filtration

450 – 1000

1.39 – 3.07

Recycled Water Filtration + RO + UV + H2O2

700 – 1200

2.16 – 3.68

Sea Water

Reverse Osmosis

Filtration + RO

800 – 1500

2.45 – 4.60

 

SOURCE: Jonathan Loveland, Black & Veatch, Santa Barbara April 13, 2017

Dr. Katherine Bell, Ph. D, P.E., BCEE, Stantec:

Dr. Bell’s practice at Stantec is to help communities develop and implement water reuse strategies. Dr. Bell stated that potable reuse of wastewater is now a “…key element in meeting water supply demand nationally.” The drivers for these strategies are limited source water availability, aggressive conservation programs, reducing ocean outfall of runoff and wastewater effluent, etc. While cities are pressing forward with reuse strategies, Dr. Bell emphasizes that: “…there are no federal regulations specifically governing potable reuse in the US; nor are there any federal legal prohibitions against this practice.” This may prove to be an impediment to promoting the practice of potable reuse.

Dr. Bell described the EPA attitude about potable reuse of treated wastewater effluent as skeptical. She says EPA’s Peter Grevatt who has reasonably expressed concerns about the capacity and ability of local wastewater operators/systems to manage the quality of the water, and the ability of utilities to finance reuse systems and provide adequate technical expertise. It is Dr. Bell’s opinion that if EPA does not step in to provide a regulatory framework to move forward utilities and cities will not act to grow reuse.

EPA has the authority to establish guidance for consistent potable reuse that can help states and local governments in developing and implementing effective potable reuse planning under the existing laws/rules – Clean Water Act (CWA) and Safe Drinking Water Act (SDWA). Her presentation points out a half dozen questions that can and should be addressed. For example, at what point does treated wastewater or stormwater discharge is no longer effluent, and where it becomes a drinking water source? Are engineered treatment systems (ponds and engineered wetlands) excluded from the definition of “Waters of the US”; or, do these count as engineered buffers in planned Indirect Potable Reuse scenarios?

By | 2017-05-08T13:52:47+00:00 May 8, 2017|Environment, Mayors Water Council, Updates|

About the Author:

Rich Anderson is the Managing Director of the Mayors Water Council.