Stream monitoring is an important component of stormwater management. Each year, volunteers are needed to take water samples from various local streams. These samples are sent to a lab and analyzed.
Which Pollutants/Nutrients does the Stream Team Monitor?
Phosphorus is an essential nutrient for plants and animals in the aquatic food web and is naturally limited in most fresh waters. Due to this, even a modest increase can set off a chain of undesirable events. Such events include algae blooms, accelerated plant growth and low dissolved oxygen levels in water. This can result in the death of aquatic plants and animals. Additional phosphorus can enter waterways from a variety of sources. This includes wastewater treatment plant discharges, failing septic systems, manure storage areas, pet waste, fertilized lawns and cropland, and streambank erosion.
The Vermont Water Quality Standards currently set no specific standard for phosphorus levels in Class B waters below 2500 feet in elevation. The State of Vermont has proposed amendments to the water quality standards to set a limit of 27 µg/L for Class B warm water medium-gradient streams. Phosphorus concentrations exceed the proposed standards at all sites measured.
The Stream Team monitored Nitrogen in 2012 and 2013. However, due to the low levels present in all samples, we did not continue monitoring for Nitrogen in 2014 and beyond.
Nitrogen exists in water in numerous forms, two of which are nitrate (NO3) and nitrite (NO2). Of these two forms, nitrate is usually the most important to measure because it is more commonly found in surface waters. Nitrate is an essential nutrient for growth of algae and other aquatic plants, and can be present at high levels due to a variety of sources. Sources of nitrogen in waters can come from wastewater treatment plants, runoff from fertilized lawns and cropland, failing on-site septic systems, runoff from animal manure storage areas, and industrial discharges. The Vermont Water Quality Standards standard for Nitrogen in Class B waters is 5.0 mg NO3-N/L. None of the site exceed the standard for Nitrogen recommended by the state.
Chloride is a component of salt found naturally in minerals and in oceans. Elevated chloride levels in surface waters can lead to poor health and reduced reproduction in aquatic species, according to the Vermont Surface Water Management Strategy. The sources of chloride in water include road deicing salts, wastewater from industries and municipalities, and leachate from landfills. The current water quality standard for chloride is 230 mg/L. The highest chloride concentration measured by the Stream Team was found at Centennial Brook in 2012, with a reading of 468 mg/L
The turbidity of a water sample refers to its cloudiness. This measurement is based on the amount of algae, microbes, and sediment suspended in the water. Turbidity measurements can be used as an indicator for erosion and/or nutrient concentration. Higher turbidity levels can indicate a higher chance of disease-causing organisms being present. The Vermont Water Quality Standards state that turbidity should not exceed 10 NTU (nepholometric turbidity units) in cold-water fish habitat and 25 NTU in warm-water fish habitat. The highest turbidity levels observed were in Morehouse Brook in 2013, with a measurement of 182 NTU, however the annual average measurement for 2013 was 42.75 NTU.
TSS (Total Suspended Solids)
Suspended solids are defined as particles that will not pass through a 2-micron filter; these particles include: silt, clay, plankton, algae, fine organic debris, and other particulate matter. High concentrations of suspended solids in a waterbody can potentially carry pollutants that cling to suspended particles, such as pesticides from crops. Like turbidity, total suspended solids impact water clarity, which makes it harder for light to pass through the water and therefore decreases photosynthesis. Water with a high concentration of TSS warms more rapidly and holds less oxygen, altering the aquatic habitat. The sources of TSS include industrial discharge, sewage, fertilizers, road runoff, and soil erosion. TSS is measured as a weight of TSS per volume of water (mg/L). There are no quantitative criteria for TSS. Vermont Water Quality Standards state that TSS concentrations “should not exceed an amount that would prevent the full support of uses.”
Escherichia coli (E. coli) is a species of fecal coliform bacteria that is specific to fecal material from humans and other warm-blooded animals. The microbes can cause short-term health effects such as diarrhea, cramps, nausea, headaches, and other symptoms. E. coli exposure may pose special health risk for infants, young children, and people with severely compromised immune systems. The Vermont Water Quality Standards state that E. coli exceed a geometric mean based on at least 3 samples obtained over a 30 day period of 18 organisms/100 ml; the Vermont safe standard for E. coli in recreational waters is 77 colonies per 100ml. Currently, the Stream Team only monitors E. coli data at Wheeler Nature Park.