Map provided

Attack of the orange cones along Pleasant Hill Road? Drivers wondering what's up with the bright fluorescent traffic channeling devices should be happy to know they are not the work of invading aliens; rather they are part of a Central Contra Costa Sanitary District (CCCSD) project increasing sewer capacity. Crews will be installing, replacing and rehabilitating about 5,600 feet of six-inch diameter to 18-inch diameter sewer pipe along Pleasant Hill Road between Springhill Road and Deer Hill Road as well as the residential neighborhood between Stanley Boulevard and Highway 24.

Cones and electronic signage are already up and stacks of green pipe are waiting, at the staging area across from Acalanes High School, to be installed. Flaggers were at work directing traffic around a lane closure on Stanley Boulevard last week. High school students and staff should be relieved that construction along Pleasant Hill Road was specifically designed to be completed by August 12, 2011 - prior to school starting.

How much capacity is enough? According to Chris Carpenter, Community Affairs Representative of CCCSD, pipes in this area date from 1948 - 1949; increasing capacity will improve wet-weather flows and accommodate more than sixty years of population growth.

The existing sewer line runs right through Acalanes High School - adjacent to buildings and directly through the baseball diamond. "Replacing it would be quite disruptive to the school," said Carpenter. Hence the installation of a brand new 18-inch diameter relief sewer line along the southbound lane of Pleasant Hill Road. A number of nearby smaller-diameter residential sewer mains are in poor condition, so they'll be replaced. Total cost of the project is $1,729,000.

Three types of installation will be used: Open Cut - using heavy equipment to cut a trench; CIPP or "cure in place pipe," which is the "least intrusive way," mentions Carpenter, to address the pipes running through four backyards; and finally Guided Boring - using a machine to tunnel under the street - a more challenging process near the intersection of Deer Hill Road and Pleasant Hill Road. This method is used to avoid other utilities in the area - CCCSD does not want to dig through water or electrical service.

CCCSD is responsible for safe and effective wastewater collection treatment and disposal. Everything that ends up in their pipes eventually flows to their wastewater treatment facility near the intersection of Highway 4 and Interstate 680. Although the upgrade is meant to handle peak wet-weather flows, if you brush your teeth, take a shower or flush the toilet you contribute to wastewater.

Forty five million gallons of wastewater is treated per day for close to half a million residents and 5,000 businesses in central Contra Costa County before it's discharged into Suisun Bay or recycled for landscape watering.

Look for the continued saga of the orange cones this month at the South Orinda Sewer Renovation project - now in its fifth phase. CCCSD will be replacing or renovating 11,000 feet of aging sewers there.