In April 2015, a contractor working for the East Bay Municipal Utility District (EBMUD) inadvertently discharged cellular concrete to a storm drain system that connects to Glen Echo Creek in Oakland. Cellular concrete was distributed downstream along in the creek for approximately 0.5 miles. Water quality effects related to the concrete release including elevated pH and deposited concrete fine sediments in the creek channel were observed almost 1 mile from the point of origin. EBMUD responded rapidly to the spill by removing the spilled concrete from the channel.
In July 2015, EBMUD contracted with Horizon to evaluate the affected spill area and develop a restoration and monitoring plan (RMP). Horizon’s site evaluation included assessing (1) the physical and geomorphic conditions in the channel and adjacent areas, (2) riparian habitat, (3) the benthic macroinvertebrate community, and (4) water quality. Based on results of the site evaluations, Horizon developed a restoration and monitoring plan to revegetate affected areas and augment instream gravel deposits to help restorebenthic habitat and monitor the benthic community and channel morphology. Horizon’s approach and plan was accepted by consulting regulatory agencies and the restoration and monitoring plan was implemented in 2016 and conducted through 2018.