Monitoring of underground leakage of petroleum products is continuing near and around the Chevron Station in Idyllwild.

RM Environmental Inc. of Calimesa continues to monitor the site semi-annually for the presence of various hydrocarbons. The latest results, reported last month, detected total petroleum hydrocarbons, including methyl-tertiary-butyl ether, benzene, toluene, ethylbenzene, and xylenes on the site and in some wells further along Highway 243.

The concentrations varied among the monitoring wells. For example, the benzene and toluene concentrations in monitoring well 6A were more than 10,000 micrograms per liter, but still half or less compared to 2014. MTBE was not detected in that well but was in MW 7A and the concentration was nearly 90 percent less than a year ago.

RM Environmental will continue to monitor the site and recommended installing two more monitoring wells.

Also, it recommends that a soil vapor extraction test be conducted later this year. If the results indicate that SVE remediation be implemented, that will take about three years to complete, the report stated.