Water Testing Update, February 2009
Lead and Copper – First round of samples collected on August 28, 2008. See below:
The Lead/Copper samples collected and submitted on August 28, 2998 were reported back to Gavilan College on September 12, 2008. The results revealed eight areas (fixtures) which exceeded the Action Level (0.015mg/l or 15 ppb) for Lead and (1.3 mg/l or 1,300 ppb) for copper.
The non-compliant samples are as follows:
Due to the samples which exceeded the AL during the August round of sampling CDPH requires that a minimum of 40 samples be drawn, one in January and one in July, in order to show an improvement in the water quality. Gavilan opted to collect an additional 51 samples (added to the original 22 samples) which made the total number of samples 73 in all.
Additionally, the eight original fixtures (out of compliance in September 2008) were replaced prior to the December sample collection.
Of the additional 51 samples collected only two new samples exceeded the AL:
The sample results in December shows a marked improvement over the September results. The original 22 samples taken on August 28, 2008 fixtures exceeded the AL for lead and only one fixture exceeded the AL for copper. Of the 73 samples taken on December 10, 2008, 5 fixtures exceeded the AL for lead and one fixture exceeded the AL for copper.
What do the above lead copper results mean?
The September sample results greater than 10% of the total number of samples tested above the MCLG (Maximum Contaminant Level Goal for Lead. This means that Lead from levels are high enough to require further sampling and initiating a WQP (Water Quality Parameter) monitoring which include testing for pH (acidity; alkalinity) and hardness in order to establish CCT (Corrosion Control Treatment).
The sample results for Copper tested less than 10% of the total number of samples tested, which means that high copper concentration in the drinking water system is unlikely. No action is necessary due to any high copper content.
Gavilan College opted to take more than the required amount of samples (73 vs. 40) in December in a good faith effort to show that the individual fixtures within critical areas tested above the MCLG for lead. The areas tested were the CDC, the Gavilan College Café, and all drinking fountains on the campus. The only fountain that tested above the MCLG was in the Gymnasium Basketball court (this fountain is turned off until it can be replaced).
Because more than 73 samples were taken in December, the results place Gavilan College less than 10% of the MCLG.