Sanctuary Integrated Monitoring Network
Monitoring Project

Central Coast Long-term Environmental Assessment Network (CCLEAN)

Principal Investigator(s)

  • Dane Hardin
    Applied Marine Sciences
Start Date: June 26, 2001

The Central Coast Long-term Environmental Assessment Network (CCLEAN) is a cooperative long-term monitoring program that satisfies the NPDES receiving water monitoring and reporting requirements of five entities including the Cities of Santa Cruz and Watsonville, Duke Energy, the Monterey Regional Water Pollution Control Agency, and the Carmel Area Wastewater District. In addition to meeting permit requirements, this collaborative meets objectives contained in a 1992 Memorandum of Agreement that established the Monterey Bay National Marine Sanctuary's Water Quality Protection Program and subsequent Action Plan entitled Monitoring, Data Access, and Interagency Coordination.

Within the framework of CCAMP (Central Coast Ambient Monitoring Program), the goal of the CCLEAN program is to assist stakeholders in maintaining, restoring, and enhancing nearshore water and sediment quality and associated beneficial uses in the Central Coast Region.

A few of the specific objectives of the program are as follows:

  • Obtain high-quality data describing the status and long-term trends in the quality of nearshore waters, sediments, and associated beneficial uses.

  • Determine whether nearshore waters and sediments are in compliance with the Ocean Plan.

  • Determine sources of contaminants to nearshore waters.

  • Provide legally defensible data on the effects of wastewater discharges in nearshore waters.

  • Develop a long-term database on trends in the quality of nearshore waters, sediments and associated beneficial uses.

CCLEAN measures inputs of possible water quality stressors and effects in nearshore waters by sampling effluent, rivers and streams, mussels, sediments and benthic communities, and nearshore waters. Effluent for each municipal discharger and rivers is sampled for persistent organic pollutants (POPs; polynuclear aromatic hydrocarbons, polychlorinated biphenyls and pesticides), nutrients, and suspended sediments using automated equipment to obtain 30-day flow-proportioned samples in the dry season and in the wet season.

Sixteen streams and coastal sites are sampled monthly for nutrients, bacteria, and suspended sediments. Satellite imagery is used to evaluate blooms of phytoplankton associated with discharges of high concentrations of nutrients.

Mussels are sampled at five locations to fill geographic gaps in other programs to measure POPs and bacteria. Sediments are sampled and analyzed for benthic organisms and POPs once a year at eight sites within the depositional band that has been identified by U.S. Geological Survey in Monterey Bay.

Summary to Date

  • None of the dischargers exceed permit limits for POPs (persistent organic pollutants)

  • Loads of POPs from rivers were orders of magnitude greater than those from wastewater treatment plants. For example, loads of DDTs from the Pajaro and Salinas rivers accounted for 98% of total loads of this POP from measured sources and averaged nearly 6 kg per year. Analysis of individual DDT compounds indicated undegraded pesticide continues to be discharged in the rivers

  • Highest loads of POPs, which are mostly adsorbed to suspended sediments, from rivers and highest concentrations of POPs in mussels were measured during the wet season

  • Analysis of satellite imagery indicated strong same-day correlations between high flows from the Pajaro River and elevated sea surface suspended sediments along the northern shore of Monterey Bay

  • Concentrations of some legacy agricultural pesticides in mussels along the northern shore of Monterey Bay were strongly correlated with antecedent rainfall, and the strongest correlations occurred near Moss Landing

  • The relationship between rainfall and legacy pesticides in mussels has not changed over the past 30 years, suggesting the sources of pesticides have not attenuated

  • Mussels at several sites in Monterey Bay exceeded the California Office of Environmental Health Hazard Assessment human-health alert level for the legacy pesticide Dieldrin, at least once

  • Waters 5.5 miles offshore in northern Monterey Bay exceeded California Ocean Plan objectives for PCBs in all three samples, and for Dieldrin, and PAHs in at least one of three samples analyzed, to date

  • Sediment concentration of DDTs at all sites exceeded the NOAA Effect Range Low (ERL)

Monitoring Trends

  • Results suggest that discharges from the Pajaro and Salinas rivers, predominantly during the wet season, exert a strong influence on water quality in the northern bight of Monterey Bay and that contaminants from these sources are impairing beneficial uses
  • Sources of legacy pesticides have not attenuated over the past 30 years


For an overview of the CCLEAN program from 2001 through 2006, please use the link provided in the 'website links' section below.

Study Parameters

  • Other nutrients
  • Sedimentation
  • Choliform
  • Organics
  • DDT

Figures and Images

Map 1. Locations of major wastewater discharges and rivers to be sampled twice per year in the CCLEAN program.

Map 2. Locations of streams and rivers to be sampled monthly in the CCLEAN program.

Figure 1. Comparison of cumulative total loads from 20022006 of DDTs (in grams) from rivers and wastewater treatment plants. Y-axis is Total Four-year Load of DDts (grams).

Figure 2. Mean dry season and wet season daily loads of DDTs from the San Lorenzo, Pajaro, Salinas and Carmel rivers in 20022003, 20032004, 2004-2005 and 2005-2006. Y-axis is Mean Load of DDTs (grams per day).

Figure 3. Relationships between lipid-normalized DDT concentrations in mussels and rainfall at six National Status and Trends Mussel Watch program sites. Rainfall data from Salinas were used for Point Santa Cruz, Elkhorn Slough, Moss Landing and Lovers Point. Rainfall data from San Luis Obispo were used for Point San Luis and San Simeon. Y-axis is Concentration of DDTs (ng/g lipid).

Figure 4. Wet-weight tissues concentrations of dieldrin in mussels from five CCLEAN sites compared with the OEHHA screening value. Mussels were collected in February 2002, October 2002, February 2003, August 2003, March 2004, August 2004 and February 2005. Y-axis is Concentration of Dieldrin (ng/g of wet weight).

Figure 5. Comparison of PCBs measured in the 2004 wet and dry seasons and in the 2006 wet season at two Monterey Bay sites with 30-day average water quality objectives in Table B of the California Ocean Plan. Y-axis is Concentration of PCBs (ng/L).

Map 3. Current CCLEAN and National Status and Trends Sampling locations.