Arsenic Case Study - POU Reverse Osmosis

Michaels Ranch, Arizona

Michaels Ranch is a small community owned water system located in rural Arizona. Michaels Ranch currently consists of 20 households, with 15 to 20 sites open for future growth. Michael's Ranch obtains its water directly from a single well, which is pumped to a holding tank prior to distribution to the community. There is no treatment of the water prior to distribution to the community.

Michaels Ranch has an established HOA, and has decided to include the parameters of the reverse osmosis program directly in to he CCR guidelines of the HOA.

Similar to other pilot program starts, an initial meeting was held at the Michael's Ranch Water Users Association (MRWUA) board meeting, and included members of the WRWUA Board, Michaels Ranch residents, ADEQ and Watts Premier. This initial meeting was used to discuss the upcoming arsenic rule, overview of a pilot project, cost, time frame, number of individuals, and the overall goals.

Following the meeting the MRWUA Board voted on the community proceeding with the POU RO program. MRWUA unanimously agreed to proceed with the POU RO install. Following the vote, MRWUA bonded a local plumber in order to perform the installation and maintenance of the reverse osmosis systems in Michael's Ranch.

MRWUA then drafted a letter explaining the arsenic project, and sent it out to the Michaels Ranch community. ( Copy of the letter sent to the Michael's Ranch community ).

The RO units used for this project were the new Watts Premier WP-5 Manifold systems. These systems are equipped with a TDS monitoring faucet, three pre filters, one 5 micron sediment and two 5 micron carbon blocks. Following the prefiltres is the 25 GPD RO

All RO were installed in to the Michaels Ranch community with in three days, on average taking 20 minutes to install the RO.Typically there was an additional 10 to 20 minutes on average where we spoke to the homeowners about the project and answered questionsthat they had about the project, as well as other plumbing and kitchen appliance concerns. All participants were left with a project overview hand out and the first of three surveys. The project overview handout was put together in order to provide background informationabout regulations, arsenic, reverse osmosis and the schedule of the project.

In conversations with the homeowners, this was an important part of the program as most of the homeowners reviewed the hand out and felt better informed and more a part of the project. Additionally, the document provided directions and telephone numbers in the event of an emergency, which provided reassurance to the homeowner on the operation and maintenance of the project.

At this time the initial set of surveys were also collected two methods were used for water analysis. First there was onsite testing through the use of Hach test kits. These test kits were able to test for arsenic, alkalinity, total and free chlorine, hardness, iron, pH and TDS. Samples were also obtained through the ADEQ for wet lab analysis. The second test a wet lab has parameters for the analysis that included arsenic, alkalinity, hardness, iron, bacteria, fluoride and manganese.

In both cases, filtered and non filtered water samples were obtained. This is in order to determine the efficiency of the reverse osmosis unit in each residence.

Michael's Ranch Water Characteristics

Survey Results


Further updates, results and survey results will be posted as they are received. The Michael's Ranch project is estimated to be completed in between September and October 2004.