Basin Water, Inc

Evaluation and Selection of a Full-Scale Arsenic Treatment System in California

By Don Bartz, General Manager, Baldy Mesa Water District

Like many other water purveyors in the same predicament, Baldy Mesa Water District (BMWD) is faced with finding a viable treatment process for arsenic removal that can be approved and implemented by January 2006.

There is little time to waste, as the District has less than two years to evaluate and install a treatment system at all nine of their well sites. Additionally, BMWD must be prepared to meet a standard for arsenic levels that has yet to be determined by the State of California , and which is rumored to be substantially less than the Federal limit of 10 ppb.

BMWD is an independent Special District, formed in 1965 to serve water to an area in the high desert of Southern California . BMWD encompasses approximately twenty-four square miles within the Victor Valley , west of the I-15 freeway, serving residents of the City of Victorville .

The District has approximately 5,500 service connections and is 100% dependent on local groundwater. The groundwater is pumped to the system from nine wells that produce a combined 7,724 gallons per minute. The District has seven storage reservoirs with a total storage capacity of 14.4 million gallons.

Since all nine wells in the system exceed the new Federal EPA standard for arsenic of 10 ppb, the District has been actively involved in evaluating various technologies for arsenic removal.

In 2002, BMWD and its neighbor, Victor Valley Water District, engaged an outside engineering firm to perform a small-scale (20 gpm) pilot project that tested iron medias to determine their expected performance and economics. Basin Water performed an additional demonstration at the same location using a 100 gpm packaged ion exchange system for arsenic removal.

1,000 GPM Arsenic Removal System at Baldy Mesa Water District.

When considering and evaluating potential arsenic removal technologies, the District was looking at several key factors. The most important of these factors were: (1) Capital Costs, (2) Operating Costs, (3) Handling Arsenic Residuals, (4) System Reliability and (5) Delivery Time. Using these factors as a guideline, BMWD was intrigued by the proposed packaged ion exchange system.

Capital Costs: The cost to purchase and install a treatment system is critical to evaluate the economics. BMWD was estimating the capital costs to be in the neighborhood of one million dollars per site (nine million total), which would have a significant impact on the capital improvement budget of the District. Basin Water's proposal includes a flat unit fee per acre-foot of treated water (no initial capital expenditures beyond minimal site improvements), and would allow the District to maintain more money for other capital improvement projects.

Operating Costs: The actual operating costs for an arsenic removal system is often underestimated. These costs include more than just utilities, chemicals and general O&M costs. Other costs would include media replacement, residuals disposal, disposal of backwash water, costs related to a system pressure drop and additional sampling. Many of these costs are part of the unit fee. Additional cost savings may be realized through the use of a proprietary computer simulation program, which predicts optimum plant operation under conditions of varying water composition. The system includes twenty-four hour remote monitoring and troubleshooting via phone line.

Arsenic Residuals: In California , hazardous waste resulting from a treatment process is a key consideration. Iron medias and ion exchange will both produce solids that will need to be disposed of in a Class I landfill. This is a complex area, which can have a detrimental impact to the overall costs of an arsenic treatment system. The cost estimate includes a negotiated fee for the disposal of the waste to a suitable site.

System Downtime: This is a key consideration for any water purveyor, but even more critical for a District requiring treatment at all of their wells. It is imperative that any system downtime be kept to a minimum. A full-scale project for an extended period of time would be very beneficial in demonstrating the reliability of a treatment process.

Delivery Time: Two years and counting! Important factors include a guaranteed delivery schedule by the supplier, and a technology that has been accepted by the California Department of Health Services.

The demonstration unit provided by Basin Water processed 2.2 million gallons, resulting in a waste product of 0.05% (1,100 gallons of waste brine). With ongoing optimization and no pH adjustment required, this processing unit's onboard computer continuously logs operating data, including pressure, flow, pH, alarms, equipment status and control actions. This low capital alternative allows for the District to pay as water is delivered (with a contract to treat a minimum number of acre-feet per year). BMWD is not responsible for financing, designing, building, installing or maintaining the wellhead treatment system.

Based on these criteria, Baldy Mesa Water District has contracted with Basin Water to supply a 1,000-gpm (full-scale) high efficiency treatment system for its Well No.1. The California Department of Health Services approved the turnkey approach, and the system went online in early January 2004. This technology is able to treat arsenic to non-detect levels, which puts BMWD in a position to meet the potentially lower standard anticipated in California . The District is also confident that the packaged system will ensure compliance with the 2006 Federal Arsenic deadline.


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> News Home Evaluation and Selection of a Full-Scale Arsenic Treatment System in California Click to view PDF Reprinted from Source CA -NV- AWWA,Vol 17, No.1 (Spring 2004), by permission. Copyright ©2004, California-Nevada Section, American Water Works Association By Don Bartz, General Manager, Baldy Mesa Water District Like many other water purveyors in the same predicament, Baldy Mesa Water District (BMWD) is faced with finding a viable treatment process for arsenic removal that can be approved and implemented by January 2006. There is little time to waste, as the District has less than two years to evaluate and install a treatment system at all nine of their well sites. Additionally, BMWD must be prepared to meet a standard for arsenic levels that has yet to be determined by the State of California , and which is rumored to be substantially less than the Federal limit of 10 ppb. BMWD is an independent Special District, formed in 1965 to serve water to an area in the high desert of Southern California . BMWD encompasses approximately twenty-four square miles within the Victor Valley , west of the I-15 freeway, serving residents of the City of Victorville . The District has approximately 5,500 service connections and is 100% dependent on local groundwater. The groundwater is pumped to the system from nine wells that produce a combined 7,724 gallons per minute. The District has seven storage reservoirs with a total storage capacity of 14.4 million gallons. Since all nine wells in the system exceed the new Federal EPA standard for arsenic of 10 ppb, the District has been actively involved in evaluating various technologies for arsenic removal. In 2002, BMWD and its neighbor, Victor Valley Water District, engaged an outside engineering firm to perform a small-scale (20 gpm) pilot project that tested iron medias to determine their expected performance and economics. Basin Water performed an additional demonstration at the same location using a 100 gpm packaged ion exchange system for arsenic removal. 1,000 GPM Arsenic Removal System at Baldy Mesa Water District. When considering and evaluating potential arsenic removal technologies, the District was looking at several key factors. The most important of these factors were: (1) Capital Costs, (2) Operating Costs, (3) Handling Arsenic Residuals, (4) System Reliability and (5) Delivery Time. Using these factors as a guideline, BMWD was intrigued by the proposed packaged ion exchange system. Capital Costs: The cost to purchase and install a treatment system is critical to evaluate the economics. BMWD was estimating the capital costs to be in the neighborhood of one million dollars per site (nine million total), which would have a significant impact on the capital improvement budget of the District. Basin Water's proposal includes a flat unit fee per acre-foot of treated water (no initial capital expenditures beyond minimal site improvements), and would allow the District to maintain more money for other capital improvement projects. Operating Costs: The actual operating costs for an arsenic removal system is often underestimated. These costs include more than just utilities, chemicals and general O&M costs. Other costs would include media replacement, residuals disposal, disposal of backwash water, costs related to a system pressure drop and additional sampling. Many of these costs are part of the unit fee. Additional cost savings may be realized through the use of a proprietary computer simulation program, which predicts optimum plant operation under conditions of varying water composition. The system includes twenty-four hour remote monitoring and troubleshooting via phone line. Arsenic Residuals: In California , hazardous waste resulting from a treatment process is a key consideration. Iron medias and ion exchange will both produce solids that will need to be disposed of in a Class I landfill. This is a complex area, which can have a detrimental impact to the overall costs of an arsenic treatment system. The cost estimate includes a negotiated fee for the disposal of the waste to a suitable site. System Downtime: This is a key consideration for any water purveyor, but even more critical for a District requiring treatment at all of their wells. It is imperative that any system downtime be kept to a minimum. A full-scale project for an extended period of time would be very beneficial in demonstrating the reliability of a treatment process. Delivery Time: Two years and counting! Important factors include a guaranteed delivery schedule by the supplier, and a technology that has been accepted by the California Department of Health Services. The demonstration unit provided by Basin Water processed 2.2 million gallons, resulting in a waste product of 0.05% (1,100 gallons of waste brine). With ongoing optimization and no pH adjustment required, this processing unit's onboard computer continuously logs operating data, including pressure, flow, pH, alarms, equipment status and control actions. This low capital alternative allows for the District to pay as water is delivered (with a contract to treat a minimum number of acre-feet per year). BMWD is not responsible for financing, designing, building, installing or maintaining the wellhead treatment system. Based on these criteria, Baldy Mesa Water District has contracted with Basin Water to supply a 1,000-gpm (full-scale) high efficiency treatment system for its Well No.1. The California Department of Health Services approved the turnkey approach, and the system went online in early January 2004. This technology is able to treat arsenic to non-detect levels, which puts BMWD in a position to meet the potentially lower standard anticipated in California . The District is also confident that the packaged system will ensure compliance with the 2006 Federal Arsenic deadline.
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Evaluation and Selection of a Full-Scale Arsenic Treatment System in California