The Washington State Department of Labor & Industries issued 247 infractions last year to people who were doing plumbing work but weren't certified plumbers.

That's up 12 percent from the previous year and nearly double the number in 2013. Meanwhile, infractions this year are rising at an even faster clip.

As a result, the L&I has started a consumer awareness campaign that includes a TV and online commercial and new website, www.ProtectMyHome.net.

In Washington, only plumbers certified by L&I can legally perform plumbing work on someone else's property. In limited circumstances, L&I-licensed electricians can do some plumbing work, such as replacing electric water heaters.

"Bad plumbing can result in extra cost and hassle for customers who have to fix faulty repairs or improperly installed toilets and other fixtures," said L&I Contractor Compliance Chief Dean Simpson. "And there are possible health effects, too.

"We've seen unqualified plumbers unknowingly allow waste water to mix with and contaminate drinking water. In other cases, improperly installed drains or venting systems have resulted in noxious sewer gases seeping into houses. No one wants that."

New consumer campaign

L&I just kicked off a TV and online ad campaign encouraging consumers to hire certified plumbers. The video spot features the voices of frustrated customers leaving phone messages for an uncertified, "Fly-By-Nite" plumber who botched their plumbing projects and appears to be vacationing in Hawaii.

Many people are unaware that plumbers have to be certified in our state, and don't know how to check whether an individual plumber is properly licensed, according to L&I.

To become a journey level plumber in Washington, applicants must have four years of classroom and on-the-job training before they can even take the certification exam.

Once certified, plumbers must have their L&I-issued, credit-card-sized certification card available for inspection when they're on the job. The plastic card includes their name, certification level and expiration date.

As construction booms around the state, L&I inspectors are finding that some plumbing companies are properly registered as contractors, but are sending uncertified plumbers or trainees without proper supervision to jobs. That's against the law, too.

Plumbing trainees and apprentices, who also must have L&I-issued cards, may work on jobs only if they are supervised by a journey level or specialty plumber.

"Companies typically charge consumers the rate for certified plumbers even if the plumber who shows up at the door is uncertified," Simpson said. "Get your money's worth and protect your investment: Hire a state-certified plumber."