The project community and equipment were selected by a project management group (PMG), organized by NSF International and consisting of representatives from the U.S. Environmental Protection Agency, Association of State Drinking Water Administrators, American Water Works Association, National Rural Water Association and the Water Quality Association.
Community. Grimes is a small, predominantly bilingual farming community located 45 miles northwest of Sacramento, Calif. It has a raw water arsenic concentration of 25 ppb, evenly split between arsenic III and V.
Equipment. A Kinetico, Inc. activated alumina (AA) device was selected by the PMG. The device featured two AA cartridges in series followed by a granular activated carbon cartridge. The POU system was designed to be installed under the sink with a separate drinking water tap. It had an automatic shutoff device set to activate after 500 gal.
The system was tested both at the NSF testing laboratory and in Grimes to verify performance. Results met the California Department of Health Services criteria of <2µg/L of arsenic instead of the MCL, as a precaution.
Because Grimes residents were mostly unaware of the high arsenic levels in their water, NSF and the PMG sent a letter to residents that described the project and invited them to an informational community meeting. Included with the letter was a list of questions and answers providing insight into the project.
“We held a town meeting, which was very helpful because everyone had a chance to learn about the project and cooperate,” said Art Olivares, board member of the Colusa County Water Works 1 in Grimes.
The meeting was attended by 15 POU study representatives and 32 residents. The presentation began with a brief background of the new arsenic rule and the implications for small communities, as well as the goal of the project.
Randy Orella, owner of Blue Fountain Water, the area’s authorized Kinetico dealer, described the unit installation process. He and other study representatives then answered attendees’ questions. Some of these questions included:
- Is the change in the water quality standard really necessary?
- Are private water supplies forced to comply with this standard?
- What are other options to deal with the new arsenic rule?
- How much is this going to cost the community?
- How much can the proposed system reduce the arsenic level?
- Does a hole have to be drilled in the sink?
- Could other locations in the house be treated?
- How is the community supposed to dispose of the spent media?
Overall, the meeting served to address many of the residents’ concerns.
“We needed to educate residents about the project, tell them how long it was going to take, how much it was going to cost, etc.,” Olivares explained.
Installations began in July 2002. Blue Fountain Water called all residents in advance to schedule installation times.
According to Mark Brotman, research scientist for Kinetico, general installation procedures included the following steps:
- The installer arrived at the house, introduced himself and asked to be shown the kitchen plumbing.
- An assessment was made of the configuration, and the installer obtained the required parts.
- The installer then turned off the water to the kitchen or the household.
- The under-sink plumbing was adapted, usually with a tee, to provide flow to the new arsenic treatment device.
- The bracket for the cartridge system was mounted in a location that provided easy access for change-outs.
- A faucet was mounted to the sink and then connected to the arsenic filter.
- Water was restored, and the unit was flushed for five minutes.
- The installer placed a paper towel underneath the system to ensure the unit wasn’t leaking.
- Refrigerators with an ice machine were tied in as well to provide arsenic-free ice.
Residences with standard plumbing generally require a 15- to 30-minute installation. Installations in Grimes, however, took anywhere from 15 minutes to three hours.
“There were just no two homes alike,” said Blue Fountain Water’s Orella. “These were not tract homes built by a single builder, but individual homes, all built one at a time over the last 100 years. Each home had different plumbing than the one next door, so we had to adapt each one on a case-by-case basis.”
According to Perialwar (Regu) Regunathan, president of Regunathan and Associates, Inc., who helped manage the project, specific challenges encountered during the installations included:
- Wall-mount faucets where counter space wasn’t available;
- Difficulties in locating shut-off valves;
- No accessible water pipe under some sinks;
- Inferior fittings and pipes;
- Existing plumbing didn’t conform to any code;
- Original plumbing 100 years old;
- Steel kitchen cabinets caused some mounting problems;
- Inadequate space in cabinet to install filtration unit;
- Unsanitary conditions due to years of water damage;
- Crawling under house to install lines to icemakers;
- Refrigerators without rollers or fused to decaying floors;
- Protecting supply tube from freezing in unconditioned space (per home-owner’s request); and
- Dogs on the loose (bitten once).
Installers faced various other problems that made the installation process difficult. Orella reported that a few residents were out during the scheduling period and that a couple had missed their appointments.
Brotman added, “To a limited degree, the fact that a significant number of residents spoke only Spanish was awkward, but the gentlemen in charge of the town’s water [Art Olivares] helped with translations and made every effort to ensure all the people knew what was going on and what to expect.”
Community participation as measured by completed installations started slowly. By the end of the study, however, all Grimes residences were involved in of the study except for six homes, two of which already had their own RO units installed.
Sampling & Costs
Following the installations, unit performance of <2µg/L of arsenic was confirmed, and units were sampled quarterly for one year. The majority of units continued to deliver quality water throughout the study period. A few units showed arsenic levels >2µg/L, but most of these were in high-use locations such as schools, businesses or large-family homes.
Some units that were not in high-use locations produced water with >2µg/L of arsenic, but upon further investigation, Kinetico discovered that the contractor filling the activated alumina cartridges was not filling them completely, resulting in channeling through the media.
To determine the advantages of POU/POE treatment as an alternative to central treatment for arsenic reduction, the NSF/EPA study also included a detailed cost analysis of the project. According to the data, central treatment would cost $24.31 per month per household. On the other hand, using POU/POE units that are allowed to operate until the shutoff devices activate, with one half of the units sampled per year, the estimated cost would be $11.46 per month per household.
The use of centrally managed POU strategies had been very limited prior to the arsenic rule, and this project identified a number of issues that small systems would need to consider as they evaluate their treatment options.
This study showed that an adsorptive POU device can be a viable, cost-effective alternative for treating arsenic in a small community. Issues such as 100% compliance and monitoring, however, have to be worked out with relevant regulators and within the community.
“The study provided a great deal of critical insight into the education and outreach needed to assist the public in an understanding of the purpose, need and value for such an approach,” said Tom Bruursema, general manager of the NSF Drinking Water Treatment Unit Program. “What a community selects as the best approach to meet their specific needs is clearly a choice they have to evaluate and make on their own.”
After the study was completed, the units were left with the community for them to maintain. To date, Grimes residents are satisfied with the taste and quality of the water.
According to a survey conducted after the project by Stratus Consulting, 77% of Grimes residents believe their water is safer with POU, and 75% said it tastes better.
Kinetico’s Mike Hemann, who helped with the installations, said the Grimes residents were very kind and cooperative. “I enjoyed meeting the residents and felt good about my role in the project,” Hemann said. “All around, the experience was very positive.”