The EPA's latest standard for arsenic dictates that the city must get the public water supply below 10 parts per billion. The city has failed to meet the initial deadline; January 2009 was the date by which the city should have been in compliance with EPA's new rules. Although the deadline was missed, the city is at least in the process of evaluating solutions. Wednesday, August 19th, Robert Fowlie with with Camp Dresser and McKee, Inc., held a meeting to discuss his recommendations for treating Socorro's water.

Mr. Fowlie noted that Socorro Springs and the Industrial Park wells - two of the primary Socorro city water supplies - are both well above the EPA's standard of 10 ppb. Socorro Springs is about 41 ppb, while the Industrial Park well is around 25 ppb. These sources need to be reduced to 10 ppb. Arsenic has many adverse health effects, including increased rates of cancer. However, most of the effects of ingesting low levels of arsenic take years to occur, because arsenic takes time to build up in the human body. Thus, while Socorro's water supply is definitely a health hazard, it is not an acute risk, but rather a long-term risk. So, given that Socorro residents are unlikely to start keeling over right and left, in the near term, Mayor Bhasker and the City Council felt that they could take some time to evaluate the options, as well as to stall for time, while attempting to procure funding for the project. The project is going to be expensive, the estimates given by Mr. Fowlie are about $4.4 million.

Fowlie discussed the report that his firm has prepared for the city. His firm evaluated three of the more popular ways to remove arsenic from public water supplies for both efficacy and costs. Fowlie noted that some technologies, such as iron-based sorbents in particular, work well for arsenic removal, but for concentrations as high as Socorro's, such systems have problems with filters being exhausted too often, resulting in increased operating and maintenance costs.

Another technique that was evaluated is electroflocculation - a new process that is just starting to be used in production settings. This technique appears promising, but requires electricity to power aluminum plates in the filtration process. Fowlie called this process, "complex and expensive" and noted that it produces large amounts of waste solids which require special equipment for processing. For this reason, combined with the fact that the technique is not yet widespread and proven, Fowlie hesitated to recommend it.

Coagulation filtration with granular media - quite a mouthful - is another technology used to remove arsenic in water supplies. This was the option recommended as the preferred alternative by Mr. Fowlie, for several reasons. Fowlie noted that this technique is a proven technology and his analysis showed that it would be the least expensive option for Socorro's water system. For example, using the coagulation filtration with granular media process, filters could be expected to last as long as 15 years, as opposed to 18 months to 3 years for other technologies. Fowlie also noted that it is a well-established, tried-and-true technology. However, it has drawbacks in that it uses chemicals in the treatment process, because the process changes the pH of the water and chemicals must be used to bring the pH back up to the normal range. Another drawback is that this technique requires "backwashing" of the filter, to clean out solid debris that builds up in the filter. Depending on how the backwashing is performed, it can result in wasted water. In addition, backwashing yields a sludge which must then be placed into drying beds for drying, after which it must be removed for disposal.

Socorro is currently testing the coagulation filtration with granular media process as a pilot project, on a smaller scale, before making its final decision. If the pilot project goes well, it is expected that the city will proceed to pursue building a full-scale system to treat Socorro's water. The primary stumbling block at this point would appear to be the question of funding. The project is estimated to cost around $4.4 million. Socorro is trying to acquire grants from several sources, including some of the much-maligned federal stimulus money. Assuming the money is procured, construction for the full-scale project could be started as early as February 2010, with completion expected by around the beginning of 2011.

Sarah Gilstrap, with Parametrix, an environmental consulting firm out of Albuquerque, then gave a presentation about the expected environmental impacts of building the water treatment plants (there will be two facilities, one at the Socorro Springs / Evergreen area, and the other at the Industrial Park Well site). Ms. Gilstrap noted that the National Environmental Policy Act, NEPA, requires that any project receiving federal funding must adhere to the NEPA laws. NEPA requires that the potential environmental impacts of construction be evaluated. Because Socorro is quite likely to acquire at least some portion of the funds for the Socorro treatment facility from the federal government, in the form of grants, it must therefore adhere to the NEPA laws.

Ms. Gilstrap's firm evaluated the likely impacts of the Socorro treatment facility and concluded that there is "no significant impact". The main environmental concern that was noted is the endangered species, the Socorro Isopod. Gilstrap claimed that with careful placement of the buildings and infrastructure, she believes that the impact on the Socorro Isopod would be negligible.

The public has 15 days, after the meeting (of August 19th) to submit written comments on the NEPA finding of no significant impact. Comments can be sent by email to: sgilstrap@parametrix.com or mailed to: Attn: Sarah Gilstrap, 8901 Adams St. NE, Suite D., Albuquerque, NM 87113. Ms. Gilstrap can be reached at 505-821-7131, for questions concerning the NEPA documentation.