The Department of Ecology has fined Sound Transit and PCL Construction Services $79,000 for water-quality and permit violations along the Tukwila section of the Central Link light rail line.

Ecology staff documented numerous violations from October 2006 through March of this year during construction of the light rail route between Sea-Tac International Airport and Seattle.

The most significant of these, accounting for $40,000 of the penalty, was the project's lack of an adequate stormwater pollution prevention plan, which the state requires.

Had such a plan been in place and followed, other violations would have been prevented.

Stormwater runoff from construction sites is a concern because muddy water in streams can cover spawning areas and suffocate salmon eggs. It also can clog gills, making it harder for salmon, trout and other fish to breathe.

Sound Transit is responsible for reporting its own water-quality and permit violations to the state.

"While we have received frank and honest violation reports, prevention is better," said Dave Peeler, who manages Ecology's water quality program.

"In the last two months, we've seen a noticeable improvement in planning and prevention, which translates to cleaner water."

Sound Transit Link Light Rail Deputy Executive Director Joe Gildner added, "When Sound Transit becomes aware one of its contractors has encountered problems with stormwater control, we report the situation promptly and work with the contractor and the state to get the issue corrected."

Sound Transit and PCL may appeal the penalty to Ecology and to the state Pollution Control Hearings Board within 30 days.

The penalty is the fourth Ecology has issued for similar violations of the project's construction stormwater permit along the 15.6-mile route.

Two of the earlier fines-$66,000 last October and $4,000 in October 2005-also applied to the Tukwila segment, which drains into Gilliam Creek and the Duwamish River.