By NOAH BUHAYAR

On a recent morning, Peter Avila was checking out the exterior of Marshall Elementary, on the corner of Capp and 15th Streets, when he came to a newly installed gate. He took off his belt and dangled it through the space between the bars. Then, reaching with his free hand, he grabbed the loose end of the leather and pulled firmly. The gate opened.

“There’s your security system,” he said, showing how easily the homeless can sneak through the gate and encamp near a dumpster, leaving behind trash, needles, urine stains and human feces.

Throughout the Mission District, elementary school administrators are pushing back against the blight of graffiti artists and vagrants to maintain sanitary conditions for students. Pushing, literally. With broom in hand, Avila—a new principal with a master’s degree from UC Berkeley—begins his rounds at Marshall at 7 a.m., often going back for a bucket, brush and gloves.

Bryant Elementary, on York and 22nd Streets, has already been tagged by graffiti artists this year.

A recently installed wheelchair ramp was meant to be an improvement but ended up creating a cozy alcove that the homeless easily find. A few days ago, Avila arrived to find the spot littered with cardboard, crumpled newspapers and human feces. Instead of waiting for district officials or workers from the Department of Public Works, he cleaned it up himself.

“This is Shangri-La for a homeless person,” he said, pointing to a space near the dumpster. The other day Avila said he found a wire hanging from the gate—evidence of yet another break in.

District officials estimated that they spend some $20,000 a year—just on the six elementary schools in the Mission—to paint over graffiti and pick up trash. That money is in addition to the approximately $4 million the Department of Public Works estimated it spends city-wide to clean up after graffiti and illegal trash dumping.

Charles Addcox, the principal at Leonard R. Flynn Elementary on the corner of Cesar Chavez and Harrison Streets, said that vandalism is an ongoing problem. His building gets “tagged” at least once a week. On one occasion last year, the entire building was covered.

The problem has been even more acute at George R. Moscone Elementary, a 340-student school on Harrison and 21st Street. Principal Susan Zielinski said she went through periods in which her building was hit daily. To ensure that the graffiti was covered up quickly, she asked the district’s maintenance crew to drive around with extra paint matching the building’s colors in the back of their truck. So far this school year, the building hasn’t been touched.

The one school in the Mission that seems to have avoided the brunt of the vandalism is César Chávez Elementary on 21st and Shotwell Streets. According to Adelina Arámburo, the principal, her building gets hit once every other month, with maybe one large act of vandalism a year. Last year, there were no major incidents.

The secret: César Chávez is used for a lot of community events outside of school hours, Arámburo said. And the gates are left open over the weekend so that community residents can use the school yard.

Last year the school did have a problem with homeless people climbing into the garden and camping out, Arámburo said. But raising the gate around it seemed to deter most of them.

When she does find a homeless person on the grounds, Arámburo, ever proper, said she asks them to move. “Almost always I’ve been able to say, ‘Excuse me, can you get up and leave. The children are about to come,’” she said. And the person leaves.