Monitoring results were at the performance goal of 1.5 µg/L on May 12 and May 28. The detections were noted at the Colusa Basin Drain 5 and Butte Slough 1 sites. On June 2, the duplicate sample for quality control had an exceedance of 1.8 µg/L while the standard lab result was at 1.2 µg/L. The samples were from the Colusa Basin Drain 1 site outside Knight’s Landing. All sampling results recovered to non-detection levels on June 4.  

These are impressive monitoring results, considering the recent weather challenges throughout the Sacramento Valley. 

Note: Thiobencarb water quality monitoring results are measured in micrograms per liter (µg/L), which are expressed as  parts per billion.