BOARD AGENDA MEMORANDUM
SUBJECT:
Title
Water Quality Provisions: Recreational Watercraft Limits at Calero, Anderson and Coyote Reservoirs.
End
RECOMMENDATION:
Recommendation
Approve lifting the daily limit on recreational watercraft launched at Calero, Anderson, and Coyote Reservoirs.
Body
SUMMARY:
Under the Master Reservoir Lease, the Santa Clara County Parks and Recreation Department (Parks) currently restricts vessels allowed to launch on Calero, Coyote and Anderson Reservoirs to prevent water quality impacts associated with certain boat fuel constituents.
To assess current water quality conditions, District staff evaluated water quality data from Anderson, Calero, and Coyote reservoirs for the following gasoline constituents: Methyl Tertiary-Butyl Ether (MTBE) and BTEX compounds (Benzene, Toluene, Ethylbenzene, and Xylene). The results indicated that these compounds are no longer detected in these reservoirs, therefore, the conditions that support launch restrictions to protect water quality no longer exist.
Background
The Master Reservoir Lease (1996, amended 2016) between Parks and the District specifies the right to limit or restrict any recreational use as necessary to meet water quality requirements, when the District determines that there is or threatens to be a significant degradation of water quality associated with such activity.
On March 3, 1998, the Board directed District staff to work with Parks staff to develop a strategy for controlling the impact of MTBE, a chemical compound resulting from the incomplete combustion of gasoline in recreational watercraft, on the District’s reservoirs. At the April 21, 1998 Board Meeting, the Board approved the proposed strategy, which included managing the number and type of watercraft allowed on the reservoirs, and extensive water quality monitoring. At that time, the goal was to maintain MTBE concentrations in treated water below 10 micrograms per liter (µg/L).
In March 1999, the Board approved a recommendation reducing the goal to keep MTBE concentrations below 3.0 µg/L. This strategy provided a margin of safety to ensure that the MTBE drinking water standard of 5.0 µg/L would not be exceeded.
The District has conducted monitoring for Volatile Organic Compounds, including MTBE and BTEX compounds, on a weekly basis during high recreational season, including special monitoring immediately following high traffic weekends, and monthly for the rest of the year.
Evaluation
In 2004, California banned MTBE as a gasoline additive. Monitoring in the last several years has not detected these constituents following heavy use periods, and after consultation with State Water Resources Control Board Division of Drinking Water, MTBE and BTEX monitoring was reduced to quarterly in Anderson, Calero, and Coyote reservoirs above the portal, and monthly at Anderson and Calero force mains. Review of the last 13 years of data indicated that MTBE and BTEX have not been detected in Anderson, Calero and Coyote reservoir since the 2004 gasoline additive ban. Hence, District and Parks staff are confident that the 1998/99 conditions no longer exist eliminating the need for recreational watercraft launch limits related to potential contamination by MTBE on these reservoirs.
FINANCIAL IMPACT:
There is no financial impact to the District associated with this item.
CEQA:
The recommended action is ministerial and thus is not subject to the requirements of CEQA.
ATTACHMENTS:
None.
UNCLASSIFIED MANAGER:
Manager
Christopher Hakes, 408-630-3792