The CWC monitors six parameters at each water monitoring site. Other tests are sometimes added as they are needed (for example testing for detergent in the Urban Watch program). We use the Water Quality Objectives formulated by Central Coast Ambient Monitoring Program (CCAMP) for these parameters. Water Quality Objectives are the acceptable range for each of the parameters that results in a healthy watershed. CCAMP provides water quality objectives specifically for the Central Coast.
Air and Water Temperature
Water temperature is one of the most important water quality parameters and has direct effects on water chemistry and the functions of aquatic organisms. Temperature influences the dissolved oxygen content of the water; the rate of photosynthesis by algae and other aquatic plants; the metabolic rates of organisms; the sensitivity of organisms to toxic wastes, parasites and diseases; and the timing of reproduction, migration and aestivation of aquatic organisms. Factors which can affect temperature include sunlight energy, seasonal and daily changes, shade, air temperature, stream flow, water depth, inflow of groundwater or surface water, and the color and turbidity (cloudiness) of the water. Other factors include soil erosion, storm water runoff, and alterations to stream morphology, substrate and flow. In the Monterey Bay region, the water quality objective is that the water be less than 22 degrees Celsius.
pH is a measure of how acidic or basic (alkaline) the water is. As the pH decreases, water becomes more acidic and as the pH increases, water becomes more basic. At the extreme ends of the pH scale, (2 or 13) physical damage to gills, exoskeleton, and fins occurs. Changes in pH may also alter the concentrations of other substances in water to a more toxic form. In fresh water, increasing temperature decreases pH. Streams containing Salmon need to have a pH between 7.0 and 8.5.
Dissolved oxygen (DO) refers to the amount of oxygen dissolved in water. The dissolved oxygen concentration in water can directly affect reproduction, incubation, changes in species, and death of adult and juvenile fish and other organisms. Factors which affect the dissolved oxygen concentration in water include temperature, DO sources such as photosynthesis, DO sinks such as respiration and breakdown of organic material, and salinity. Low dissolved oxygen levels usually result from algal blooms, human waste and animal waste. Anadromous fish require high DO levels (>9.0 mg/l) during their reproductive phases. During the juvenile growth period (in the summer and fall), DO levels must remain at 8.0 mg/l or higher to prevent impairment. When DO levels fall to 6.5-7.0 mg/l, sharp decreases in performance have been observed. Embryos and larvae require even higher DO levels (State Water Resources Control Board 1996). The Water Quality Objective minimum for DO for supporting coldwater fish has been set at not less than 7.0 mg/l (Basin Plan).
Conductivity is a measure of the ability of the water to conduct an electrical current. This ability is affected by the nutrients and minerals in the water as well as various pollutants. It is also a useful way to measure sea water intrusion as the more salt there is in the water, the higher the conductivity. There is no set water quality objective for the Central Coast area. Generally, the conductivity of rivers in the United States ranges from 50-1500 ųS/cm and inland fresh water studies indicate a range between 150 to 500 ųS/cm for supporting good mixed fisheries (EPA 2003). Industrial waters can range as high as 10,000 ųS/cm (EPA 2003). However, baseline measurements in central coast watersheds are consistently found to be of elevated values normally, up to 1900 ųS/cm and beyond, as so much of the local geology consists of many mineral deposits and uplifted seafloor materials.
Turbidity is a measure of the amount of suspended particles in the water. Watersheds in general have a natural turbidity level with inputs from natural erosion, organic decay and algae. Turbidity can be an indicator of erosion, excessive nutrient loading and algal growth. Because of the number of suspended plants and animals (plankton) found within stream systems, turbid water can also be considered natural. The level of turbidity will vary from stream to stream depending on the nutrient loading, geology and stream dynamics. There has been no determination of the natural turbidity level in most of the local watersheds in Santa Cruz County. The Coastal Watershed Council uses Jackson Turbidity Units to measure turbidity and has adopted an objective of less than 20 JTU.
CWC also has a host of other tests that we run depending on the program.
Copper Copper is a mineral element; however it is used in many industrial applications. Specific to this program is the fact that surface runoff and stormwater flows pick up copper and zinc from brake and tire wear and other chemicals in vehicle wash wastewater. Concentrations over .025 mg/L are toxic to freshwater fish.
Surfactants and detergents are common contaminants of surface water due to their common usage in every type of washing and cleaning operation. Modern detergents contain more than surfactants. Cleaning products may also contain enzymes to degrade protein-based stains, bleaches to de-color stains and add power to cleaning agents, and blue dyes to counter yellowing. Detergent surfactants are made from a variety of petrochemicals (derived from petroleum) and/or oleochemicals (derived from fats and oils). The presence of detergent surfactants in a storm drain system is a strong indicator of run-off or effluent discharges. Detergents lower the amount of oxygen available to fish.
Chlorine, as Cl 2 (molecular chlorine) is highly toxic, and it is often used as a disinfectant. In combination with a metal such as sodium it becomes essential for life. Small amounts of chloride (Cl – ) are required for normal cell functions in plant and animal life. High chloride levels can cause human illness and also can affect plant growth. Taste threshold is about 250 mg/l for most people, however, calcium or magnesium chloride are not usually detected by taste until levels of 1000 mg/l are reached. Public drinking water standards require chloride levels not to exceed 250 mg/l. Very high detections in storm drain discharges could be an indicator of industrial waste waters, however low concentrations may indicate a drinking water discharge from a local source.
CWC takes water samples for lab analysis for nutrients and pathogens.
Nitrate is a nutrient that occurs naturally in water bodies and promotes aquatic plant growth. Excessive nutrient levels can lead to algal and aquatic weed growth that in turn depletes the available oxygen in the water column. Runoff containing detergents, fertilizers, animal waste, industrial waste, or sewage, contributes to elevated nutrient levels as does excess dumping of vegetative material. High levels of nutrients can cause hypoxia and eutrophication in water. The CCAMP Attention Level is 2.25 mg/L. An attention level is a non regulatory objective that helps us to measure when potential impacts may occur.
The orthophosphate test measures the amount of phosphates in the water. Phosphate is a nutrient that is not found in large quantities in streams. As a result, modest increases in it can lead to large changes in the stream conditions. Some effects of phosphates are: accelerated plant growth, algae blooms, low dissolved oxygen, and the death of certain fish, invertebrates, and other aquatic animals. Human sources of phosphate are: “wastewater treatment plants, runoff from fertilized lawns and cropland, failing septic systems, runoff from animal manure storage areas, disturbed land areas, drained wetlands, water treatment, and commercial cleaning preparations.” (Source: U.S. EPA) There is no formal water quality objective for orthophosphate but the CCAMP attention level is 0.12 mg/L.
Ammonia is excreted by animals and produced during decomposition of plants and animals. Its natural breakdown thus returns nitrogen to the aquatic system. It is rapidly oxidized in natural water systems by special bacterial groups that produce the ions of nitrite (NO2), nitrate (NO3), and ammonia nitrogen (NH3–N), which are then used by plants; therefore ammonia is an additional source of nitrogen as a nutrient which may contribute to the expanded growth of undesirable algae and other forms of plant growth that overload the natural system and cause eutrophication. The unionized form of ammonia (NH3) is the preferred nitrogen-containing nutrient for plant growth and is also one of the most important pollutants because it is relatively common, but can be toxic to animals, causing lower reproduction and growth, or death to fish and other aquatic life. The water quality objective, according to the U.S. EPA, is less than .025 parts per million.
Most coliform bacteria originate from the feces of warm-blooded animals and indicate the presence of human sewage or wildlife contamination, as well as feces-born organisms that can cause diseases such as hepatitis A, bacterial meningitis, and encephalitis. The EPA Water Quality Criteria of 400 MPN/100 ml is used as the water quality objective. Total coliform count provides an indicator of pathogen conditions in the water. Testing for “indicator” bacteria monitors the potential presence of disease-causing organisms. Indicator bacteria are types of bacteria not normally found in high numbers in oceans, rivers, or creeks but always found in sources of fecal contamination. Though they are not typically disease-causing organisms themselves, they can be indicative of the presence of such organisms. Studies have shown that when concentrations of indicator bacteria exceed certain levels in waters used for water body contact recreation, individuals exposed to these waters may have a greater chance of getting sick (http://www.ccamp.org ).
E.coli is a type of fecal coliform bacteria commonly found in the intestines of animals and humans. E. coli is short for Escherichia coli. The presence of E. coli in water is a strong indication of recent sewage or animal waste contamination, although sewage may contain many types of disease-causing organisms. During rainfalls, snow melts, or other types of precipitation, E. coli and Fecal coliforms may be washed into creeks, rivers, streams, lakes, or groundwater (http://www.epa.gov/safewater/ecoli.html ).