Cal Poly Pomona is regulated as a public water system due to the number of people on campus and the complexity of providing potable water. Routine water quality sampling is conducted quarterly at four locations to verify that the university is meeting quality standards.
In a recent sampling, levels of Total Trihalomethanes (TTHM) were found to exceed EPA guidelines by two parts per billion at one test location — Building 81, the Facilities Management offices on the southeast edge of campus. Tests at the other three locations were within the guidelines. (Results collected are averaged on a yearly basis for each respective sampling site.)
The abundance of rain in the last few months has replenished surface water supplies throughout much of the state but may have contributed to the higher TTHM level. Surface water historically contains more organic materials, which, when chlorinated, increases the potential for TTHM. On April 10, after the most recent water tests, Cal Poly Pomona’s Water Treatment Operations switched from a blend of ground water and treated surface water to a supply made up entirely of ground water treated by the newly operational reverse osmosis plant. This will reduce the likelihood that future tests will yield TTHM levels in excess of EPA standards.