Groves of eucalyptus trees in the City of Lake Forest, Calif., provided abundant landscaping for residents and severe root problems for the Irvine Ranch Water District. Despite crews cleaning hot spots three times per month and treating roots with chemical foam, blockages continued to surcharge manholes and back up sewage into homes.
In 2010, the city requested proposals to line 8- to 10-inch clay sewer mains, manholes, and 780 4-inch clay laterals. Insituform Technologies won the bid and subcontracted Quality Pipe Services of Denver, Colo., to line the service connections. About 70 percent of them had massive root balls where they
