The San Mateo County Harbor District recently reviewed upcoming and ongoing projects designed to increase water quality and recycled water use within Pillar Point Harbor.
At the Harbor Commission meeting last month, the San Mateo Resource Conservation District, a non-regulatory agency that provides technical assistance to a variety of environmental services, announced that it was partnering with the Harbor District on a stormwater capture project that could retain up to 5 million gallons each year.
RCD Water Quality Program Manager Noah Katz said the plan calls for large water tanks to be installed in the two Johnson Pier parking lots. The two parking lots together make up a combined 435,000 square feet. Based on the harbor’s average rainfall between 2018 and 2020, the system could capture and reuse around 5 million gallons a year. That would offset about 86 percent of Pillar Point Harbor’s normal water usage based on 2020 levels, Katz said.
RCD and the Harbor District submitted a grant to the California Department of Water Resources for the project. Katz said after the water is captured the district will need to build infrastructure to transport non-potable water, but RCD will also do feasibility analysis for a treatment facility to assess potable use standards.
“It will reduce the amount of contaminated stormwater entering the harbor and further ensure the harbor is not contributing to water quality impacts here,” said Katz.
At the Harbor District’s request, Katz said RCD will examine expanding the system to capture runoff further down Capistrano Road near Barbara’s Fish Trap and the Half Moon Bay Brewing Co., an area known for having unsafe bacteria levels. Harbor District General Manager Jim Pruett said one of the outfalls near Capistrano Beach is in front of the future RV park, and the district may ask the owner to join the stormwater capture system in order to reduce the district’s overall total maximum daily load limit, also known as TMDL.
“Helping us connect it to our system to prevent it from entering the harbor before it gets cleaned would help us meet our TMDL requirements and help them meet their requirements for owning that land,” Pruett said.
The RCD also shared the results of the winter’s First Flush report. The annual program tests water quality from creeks and ocean outfalls after the first big rain of the year. The RCD recruits volunteers to collect water samples and data to test quality levels, and this year’s program had 24 volunteers who sampled 13 sites on the Coastside.
The report lists potential sources for the pollutants, which include metals, nutrients and fecal indicator bacteria. Enterococcus, orthophosphates and E. coli were found at nearly all of six sites tested at the harbor. All sites exceed the pollutant threshold for enterococcus, said Nicole Schmidt, the RCD’s water quality program coordinator. E. coli and enterococcus were found at all sites. The RCD reported no concern for nitrate, lead or zinc.
The board noted that signs posted at the five Pillar Point Harbor beaches that highlight dangerous bacteria levels don’t always reflect recent data and in some cases are ignored by the public. Katz noted that there is potential for new signage that includes a flag system and altered signs describing the recent week’s water quality data two days after samples are collected. While still in the planning stage, the warning system would fly different flags indicating how safe the beach is and the bacteria levels.