Thiobencarb monitoring results report numbers at most sites on May 30 and June 4. The monitoring numbers exceeded the 1.5 µg/L (parts per billion) performance goal at the upper part of Colusa Basin Drain (CBD5) on May 30, and the lower part of the drainage (CBD1) May 30 and June 4. This now counts as seven exceedances of the performance goal into the sixth week of monitoring.
Good news is the increase in monitoring results exceeding the performance goal trend to a decrease with the highest result at 1.9 µg/L on June 4. The river site and city drinking water intakes remain at non-detectable levels for thiobencarb.
The season is almost half way over. We will extend the thiobencarb monitoring one additional week with the later start to the season.