ARVIN, Calif. -- Arvin residents are upset after they learned that they may be drinking toxic water, KERO reported.

Unsafe levels of nitrates were detected in one of five Arvin wells. Although some residents were warned, not everyone knew about the danger.

Maria Navarro is pregnant and has small children at home, but she learned about the warning from 23News.

But, according to Arvin officials, warning notices were sent in the mail and a notice was published in the Arvin newspaper that explained well No. 9 had tested for unsafe nitrate levels. The notices said pregnant women and infants should not drink the water, and that the water shouldn't be used to make formula, even if boiled.

Angelina Flores, an ob-gyn nurse, said she doesn't remember getting a notice.

"We do get mail but when anything looks like it doesn't seem too important -- if it doesn't have a flashing "warning" -- you put it off to the side," Flores said.

Arvin Community Services Director Raymond Kincy said officials sent the notices as required by the state. He added they are trying to find a solution to their unsafe drinking water problem.

"We are going to be drilling another well, so maybe we won't need this well as much. One option we'll look at is maybe destroying the well," Kincy said.

According to Kincy, this is just the beginning of Arvin's water problems. When new federal standards for safe arsenic levels go into effect in 2006, all of Arvin's wells will fall well below the safe exposure standards. Kincy said dealing with that problem could cost as much as $1 million per well.

The California Department of Health told Arvin city officials that they must have a plan in place to deal with the unsafe drinking water problem by Aug. 15.