DUBLIN -- Dublin High School soon will become the latest campus in town to switch to recycled wastewater for irrigating outdoor landscaping and fields. And it couldn't come soon enough, as water rationing nears for Dublin in response to the drought, officials say.

The high school irrigation system will switch over to recycled water in mid-May, leaving Dublin Elementary as the only Dublin public school not hooked into recycled water, school and water district officials report.

The purpose -- using treated effluent to reduce demand for fresh water.

"This is good for the community and good for the environment," said Steven Hanke, the Dublin Unified School District superintendent.

The high school switch will save as much potable water as used by 90 average single-family homes in Dublin, according to the Dublin San Ramon Services District, the water supplier for 67,000 people in Dublin and San Ramon's Dougherty Valley.

"This is a huge deal. Every gallon of recycled water used means a gallon of potable water saved," said Dan Gallagher, the district operations manager.

The switch will be relatively quick and simple. Recycled water pipes were extended to the campus in 2012 as part of much larger water project that provided reclaimed water to several central Dublin parks, schools and green ways.

High school officials had been considering hooking up for some time, and the water district's move toward water restrictions provided fresh motivation. On Monday, the Dublin San Ramon Services District board will consider drought water rate increases aimed at achieving a 35 percent reduction in water use systemwide.

High school sprinklers will be marked with bright purple coloring and signs posted on lawns to inform the public about the reclaimed water. Hanke said the school district wanted to make sure the switch didn't worry students and parents.

While water officials say the effluent is treated to kill germs and viruses, some people were concerned that infield sprinklers at the school baseball fields might release overspray into the stands.

In response, school officials decided to change the infield watering system to minimize spray. They also decided to postpone the conversion until after the high school baseball season ends in mid-May, Hanke said.

"We didn't want to cause any alarm," he said.

The Dublin High football stadium is not affected because it has artificial turf.

Dougherty Valley and California high schools in San Ramon already use reclaimed water for outdoor irrigation.

While Dublin Elementary School in western Dublin still irrigates with fresh water, the Dublin San Ramon Services District is seeking grants to extend a reclaimed water pipeline to that area of Dublin, Gallagher said.