OAKLAND -- The unseasonable weather isn't the only thing preventing residents from taking a swim this summer.

The Alameda County Department of Environmental Health temporarily has shut down several public pools, including the Piedmont Swim Club facility, in an attempt to enforce new federal safety regulations.

The department, which oversees about 1,500 facilities, estimates that 40 percent of public pools in Alameda County are not complying with the law, which requires hot tub and pool owners to install new drain covers in order to prevent users from being sucked into the drain or trapped in it.

With only 60 percent of public pools in compliance, officials are concerned. "This is a low figure, lower then we would want it to be," said Cynthia Bartus Gepsen, a supervisor in the health department.

The deadline for the upgrade was July 1. Public and private pool owners are required to upgrade their facilities; the department does not oversee private pools. The Piedmont Swim Club pool reopened Monday after it was closed July 12.

Gepsen said schools, hotel chains and clubs have been "proactive" in adopting the new standards, but homeowner associations and apartment complexes have been less willing to comply.

The new requirements were mandated two years ago as a reaction to the tragic death of Virginia Graeme Baker, granddaughter of former U.S. Secretary of State James Baker. Virginia died when the suction from a spa drain trapped her underwater.

According to the federal law enacted in December 2008, pool drains have to be properly covered. In addition, there has to be a system installed that shuts down the pumps when a blockage is detected.

Gepsen said some pool owners assert that financial constraints have prevented them from purchasing new drain systems.

Andras Szigetvari is a reporter for Der Standard in Vienna. He is a visiting journalist working for the Oakland Tribune. Contact him at andras.szigetvari@derstandard.at.