Sanctuary Integrated Monitoring Network
Monitoring Project

Santa Cruz County Beach Water Quality

Principal Investigator(s)

  • Steve Peters
    Santa Cruz County Environmental Health Services
  • John Ricker
    Santa Cruz County Environmental Health Services
Start Date: January 01, 1975

Santa Cruz County Environmental Health Service (EHS) has conducted regular testing of freshwater and saltwater swimming areas since 1968. Fecal coliform has been used as the test for freshwater during that whole period. Total coliform was used in salt water until 1994, when it was replaced by the more specific fecal coliform bacteria testing. Testing at swimming areas was performed weekly during the summer and intermittently at other times.

n 1999, EHS began testing marine waters for total coliform, E.coli and enterococcus, pursuant to AB 411. EHS currently conducts water monitoring efforts at approximately 120 sites each month throughout Santa Cruz County encompassing both fresh and marine water environments. In the past, this has included detailed investigations and extensive sampling of Lower San Lorenzo River (1997), Lower Soquel Creek and Capitola Lagoon (1987), and Lower Aptos Creek (1987).

Summary to Date

Water quality has been a concern for many years. The first report of poor water quality in the lower San Lorenzo River was presented to the County Health Officer by the State Department of Public Health by letter report dated October 1, 1953. An investigation was conducted after a routine beach survey had revealed high levels of coliform organisms “exceeding numbers generally considered safe for recreational purposes”.

Although beach water quality tends to fluctuate from year to year there does not appear to be any long term trend (Figure 1). Although the number of postings was higher in 2002 (Figure 2 and Table 3), the quality of water entering the beaches from the creeks was not significantly worse (Table 2).

Monitoring Trends

  • Bacteriologic quality is generally good, but declines in the vicinity of creek mouths during storm events and at times during the summer.
  • The highest levels of contamination and resultant beach posting occur at Rio del Mar, Capitola, and Santa Cruz Main Beach, the focus areas of this study.

Study Parameters

  • Enterococcus
  • Turbidity
  • Fecal coliform
  • Total coliform

Figures and Images

Figure 1: Trends in Summer Beach Water Quality (1975-2002)

Table 2: Percent of Time Safe Body Contact Standards Exceeded at Creek Mouths (Fecal coliform >400/100ml) (Entire Year/ Swimming season)

Figure 2: Beach Postings, 1991-2002

Table 3: Days Santa Cruz County Beaches Posted by Year 1991-2003