Giant boulders and low groundwater levels cause problems
The City of Monrovia approved an agreement with HMC, Inc., in August of 2018 to coordinate remediation efforts at the park-and-ride lot at Station Square, as mandated by the LA Regional Water Board (Board), and those efforts have been going well thus far. The Board approved a preliminary Remedial Action Plan that outlines the pathway for gaining compliance at the location. Additionally, as part of the work, the Board directed the city to coordinate additional groundwater testing, which HMC has also been coordinating at the site during the past few weeks.
In order to coordinate the groundwater testing, the Board directed the city to drill three new wells to pull new groundwater samples. The drilling work began in December 2018 and to date the city has only been able to complete drilling at one of the three required wells. A number of problems have arisen during the project. The most prominent issue is large underground boulders. During the drilling process, the team repeatedly ran into boulders bigger than cars, which damaged drilling equipment and slowed the overall process down. To compensate for that factor, the city identified a bigger air rotary drill rig that has been brought on site, and which can get through the boulders.
Another issue that arose is the fact that groundwater levels have fallen dramatically forcing the city to drill deeper than originally thought in order to hit water. Initially, the city estimated that they would have to drill down around 200–220 feet. Instead, groundwater is not being hit until the drill gets past 300 feet underground. HMC Inc. has mentioned several times that having to drill 80–100 feet deeper than originally anticipated is quite shocking, even when taking into account the current drought situation. It’s certainly a sign of how much the region has been impacted by the lack of rain during the past 10 years.
As a result of these unforeseen troubles, city staff is now anticipating cost overruns and has asked for a worst-case scenario. They anticipate needing around $60,000 to $70,000 more to offset the boulder issues and the deeper wells that need to be drilled. Staff plans on bringing a change order to the contract forward for City Council review at the Jan. 15 meeting.
