To keep pace with explosive growth in residential development symptomatic of the metro Phoenix, Arizona area over the last three years, the City of El Mirage, Arizona undertook a program to bring three new well production sites online for the summer of 2006. Groundwater is the City's only source of water. The Dietz Crane site is located in a residential neighborhood with 8-inch diameter sewer lines that run to the City's Water Reclamation Facility. The sewer lines and the wastewater plant can only receive small discharges of non-hazardous wastewater from this site. In addition, the residential neighborhoods limit the use of hazardous chemicals. In the spring of 2004, the agricultural well at the Dietz Crane site was converted to a domestic well. Samples taken at the time showed arsenic levels at 30 micrograms per liter, and the decision was made to redrill the well and develop the site into a water production facility. During drilling and construction of the well, the team performed geophysical logging, groundwater sampling and zonal construction to isolate the arsenic bearing strata. When complete, the arsenic concentration produced by the 1500 foot well was ±12 µg/L. It is always better to leave the arsenic in the ground than to have to treat the water. The well produced water at the goal of 1 mgd. The City had a challenging schedule to identify a treatment alternative and implement it before the new arsenic standard (10 µg/L) became effective in January 2006. The goals were to have a 700 gpm production rate and to reduce the arsenic levels in the well to 8 µg/L. The paper also provides information on the process selection, treatment system procurement, and start-up and commissioning.
| Edition : | Vol. - No. |
| Number of Pages : | 2 |
| Published : | 06/01/2007 |
