Monitoring of 25 CMP sites across the Central Coast region began in 2005, with samples collected on a monthly basis for conventional water quality parameters and flow/discharge, twice during the wet and twice during the dry season for water toxicity, and annually in the spring for sediment toxicity and benthic community/habitat assessments. In 2006 an additional 25 sites were added to the program, following the same monitoring schedule.
Monitoring sites are generally located at downstream locations in watersheds with substantial or predominant agricultural land use and known water quality impairments. Monitoring sites are located in the following Central Coast Hydrologic Units:
305 – Pajaro
309 – Lower Salinas
310 – Estero Bay
312 – Santa Maria
313 – San Antonio
314 – Santa Ynez
315 – South Coast
CMP field teams use multi-probe meters to collect the following conventional parameters: chlorophyll a, conductivity, dissolved oxygen (D.O.), pH, and turbidity. The other conventional parameters (e.g., orthophosphate as P, nitrate as N, and total ammonia) are laboratory-based analyses. Chronic toxicity testing of water samples has historically included an algae (Selenastrum capricornutum), an invertebrate (Ceriodaphnia dubia), and a fish (Pimephales promelas) for freshwater sites. As each of these species have limited tolerance for elevated conductivity/salinity that can naturally occur at some CMP sites, the following alternative species may be used for such conditions: a diatom (Thalassiosira pseudonana), two invertebrates (Hyalella azteca or Americamysis bahia), and a fish (Cyprinodon variegatus). The fish testing was eliminated in Ag Order 3.0 and replaced with a second invertebrate – Chironomus dilutus. Sediment toxicity is evaluated using the 10-day invertebrate Hyalella azteca test.
During certain years, water and sediment samples are also analyzed for several different classes of toxicants that may be responsible for causing toxic effects to the test organisms listed above. These classes typically include pesticides (e.g., organophosphates, neonicotinoids, pyrethroids); metals (e.g., arsenic, boron, cadmium, copper, lead, nickel, molybdenum, selenium, and zinc), and select herbicides. Organic carbon and hardness are also measured as auxiliary parameters.
Routine Field Sampling
CMP field teams complete a field log during each event that specifies what has been sampled at each site. Before and after each day of monitoring, the multi-probe meter is calibrated against standards and the calibration information is recorded into the field log. Upon arrival at each site, the field teams record the required in-field observations (e.g., water color, vegetation coverage) and take site photos. One team member than collects water samples using a stainless steel bucket while the other team member is preparing bottles with labels, filling out laboratory COCs, and populating the field log with sample collection dates/times; sample bottles are placed on ice in coolers after collection. The field team then measures several additional water quality parameters using multi-probe field meters and stream flow (velocity/discharge) at multiple points across the water body using a doppler velocity meter.
Laboratory Toxicity Test (Bioassay)
In addition to routine monitoring, the CMP has also performed focused studies on pesticides and other potential toxicants in both sediment and water, approximately once every five years throughout the program history. In 2008 the CMP also performed “upstream monitoring” in several of the most highly impaired watersheds, as well as a study of in-stream flow patterns at several sites.
Data recorded into monthly field logs are transcribed into electronic data deliverables (EDDs) formatted to be consistent with the California Environmental Data Exchange Network (CEDEN). The CMP submits quarterly EDDs to the Central Coast RWQCB, who then makes the raw data available to the public via CEDEN.
The CMP also performs data summary and analysis, which are included in an annual narrative report that is also submitted to the Central Coast RWQCB each year.