BIG BLUE RIVER WATERSHED WATER QUALITY MONITORING
Volunteer water monitoring in the watershed has occurred since 2001 using Hoosier Riverwatch methods. The Big Blue River Watershed Project has since established additional sites along the Big Blue and its tributaries, adding more volunteers and invaluble monitoring data in 2009 and 2010.
Volunteers collect data from 10 sites for E.coli every month starting in April and through October (recreational season). At eight out of the 10 sites, chemical data and streamflow are taken every other month, physical assessments are done in the spring and fall, and biological assessments, or macroinvertebrates, are sampled once a year.
CHEMICAL MEASUREMENTS
DISSOLVED OXYGEN
Oxygen is very important to life on land just as dissolved oxygen is important to aquatic life, such as fish and plants. Dissolved oxygen, or DO, is oxygen from the atmosphere that is dissolved in water until the water is saturated. The oxygen is also produced by aquatic plants, algae and plankton during photosynthesis (the process used by plants when converting the sun's light into food).
DO is measured in parts per million, or ppm*. The required amount of DO for healthy aquatic plants and animals ranges between 5 and 6 parts per million. Levels below 3 ppm are stressful and those below 2 and 1 ppm do not support fish life.
Indiana State Water Quality Standard (WQS) for dissolved oxygen is average greater than 5 ppm, not less than 4 ppm.
*ppm is also measured as milligrams per Liter or mg/L, ie. 10 ppm = 10mg/L
2009 RESULTS: Levels monitored within the Big Blue River watershed this past year ranged between 6.5 ppm at the Carthage site to 12 ppm at the Garner Street site in New Castle.
WATER TEMPERATURE
Aquatic life survives in narrow ranges of water temperature. Dissolved oxygen is affected by water temperature. The lower the water temperature, the higher the dissolved oxygen. Water temperature is also affected by the rate of photosynthesis. The higher the water temperature, the higher the rate of photosynthesis in plants which leads to increased plant death and decomposition and a higher oxygen consumption by bacteria (BOD). When water temperatures are too high (thermal) or too low, aquatic organisms die.
Natural changes in water temperatures occur with the seasons, the amount of rainfall, and how fast the water is moving. Other causes of water warm-up include: removal of riparian trees along streambanks and within the watershed, runoff from roads and parking lots and discharges from industry and wastewater treatment plants.
2009 RESULTS: Water temperatures ranged from 10 degrees Celsius (50 degrees Fahrenheit) at Little Blue River and 103 and the Big Blue River at Garner St. sites to 28.5 degrees Celsius (83.3 degrees Fahrenheit) at Big Blue River and 350 West. The lower temperatures were recorded in October while most of the high numbers were recorded in July. The greatest ranges in temperature occurred at Little Blue River and 103 and the Big Blue River at Garner St. sites with a 14.5 degree change, followed by Big Blue River at 600 N site (10 degree change) and Big Blue River at 350 W and Duck Creek at Greensboro Pike sites (7 degrees respectively).
BIOLOGICAL OXYGEN DEMAND (BOD)
Streams that have a lot of plant growth and decay or pollution generally have high BOD levels. BOD, or biological oxygen demand, is a measure of the amount of oxygen used by bacteria to break down organic wastes. Therefore, available dissolved oxygen is being consumed by bacteria robbing other aquatic organisms of the oxygen needed to live. Streams with low BOD are relatively clean and are free from excessive plant growth.
Some causes of high organic matter are effluent (outflow) from septic tanks and municipal wastewater that has not been completely treated. Also hot weather and eutrophication causes algae blooms which
Different levels of BOD indicate the presence of organic material and bacteria in the water. The levels vary depending on the characteristics of the stream being sampled. Here is a rough guide provided by Hoosier Riverwatch:
1-2mg/L BOD Clean water with little organic waste
3-5mg/L BOD Fairly clean with some organic waste
6-9mg/L BOD Lots of organic material and bacteria
10+ mg/L BOD Very poor water quality. Very large amounts of organic material in water.
Indiana's average for BOD is 1.5mg/L.
2009 RESULTS: We measure the amount of BOD 5 days after collecting a water sample. Our lowest level was 0mg/L (zero) BOD at Big Blue River at 400S and 350W and Duck Creek at Greensboro Pike. Our highest level was measured on Big Blue River at Garner St with 6.5mg/L.
NITRATES AND NITRITES
Nitrogen is present in all living organisms. It makes up about 80% of the air we breathe. Nitrates are essential for plant growth and are a main ingredient in fertilizers.
Nitrogen occurs in water as nitrate, nitrite and ammonia. It can come from manure, such as treatment lagoons and over fertilized fields. Runoff from agriculture, golf courses and lawns is high in nitrogen, especially if it rains soon after fertilizing. In the state of Indiana, sewage is the primary source of nitrates in surface water.
Additional problems can arise with nitrogen when it works with phosphorus - they increase algae growth, creating algal blooms, and cause eutrophication. Eutrophication eventually leads to a decrease in dissolved oxygen which, when concentrations are very low, leads to hypoxia such as in the Gulf of Mexico.
Generally, a nitrate level below 4mg/L is an indication of an unpolluted body of water. However, levels above 40mg/L and nitrite levels above 3.3mg/L are considered unsafe for drinking.
Indiana's average for nitrate is 12.32mg/L.
2009 RESULTS: The lowest nitrate level measured was on Big Blue River at 600 N with 0mg/L, but the site also measured our highest nitrate level at 17.6mg/L. Nitrite levels measured at 0mg/L throughout most of the sites through most of the monitoring season (April - October). However, our site at Little Blue River and 103 measured once at 3.3mg/L in July.
pH
pH is one of the most common tests when conducting water quality monitoring. Chemical reactions are always occurring in the water. These chemical reactions produce acids and bases, in which acids contain more hydrogen (H+) ions and bases contain more hydroxide ions (OH-). The pH level is important to measure water quality because aquatic organisms are sensitive to pH. A pH range of 6.5 to 8.2 is optimal for most organisms.
There are numerous natural and human activities that raise or lower the pH in bodies of water. Automobiles and coal-producing power plants, for example, release pollutants into the air and when mixed with rain creates acid rain. Runoff from abandoned mine lands, or acid mine drainage, lowers pH. Lower pH values increase the solubility of some heavy metals, such as copper and aluminum, allowing them to dissolve into the water and become toxic to aquatic organisms. Algal blooms, caused by excess nutrients, remove carbon dioxide from the water during photosynthesis, which may raise pH to 9 or more.
Indiana's average for pH is 8.0, while the state's WQS is between 6 and 9.
2009 RESULTS: The lowest pH, 6.5, was measured at 3 monitoring sites: Big Blue River at Garner St., Montgomery Creek at US 40, and near 800 N in Carthage. Montgomery Creek also measured our highest pH at 9.
ORTHOPHOSPHATES
Orthophosphates are readily available for plant uptake and are dissolved in water. Orthophosphates are mostly inorganic and are one form of phosphates. Phosphorus is essential to plants and occurs naturally in soil and animals but pollutes waters when it is present in excess amounts. Phosphorus enters bodies of water in organic matter such as dead plants and animals and manure attached to soil particles. It also pollutes in man-made forms such as dishwashing detergents, fertilizers and industry wastes. Measuring orthophosphates gives an indication of current potential for algae blooms and eutrophication.
Phosphorus cyles through many forms except a gaseous form. Once it is in an aquatic system it remains there and cycles through different forms unless it is physically removed, for example, by dredging. Over time some of the other forms of phosphates attached to particles in the water column and in the sediments (including organic forms) can be changed into orthophosphates, becoming available for plant growth. For this reason, it is useful to test for total phosphate levels. However, testing for total phosphates requires the use of a strong acid and boiling the sample for 30 minutes. Hoosier Riverwatch does not have a means of obtaining results for total phosphorus.
There are no state WQS for orthophosphate. Indiana's average for total phosphate, however, is 0.05mg/L. Generally, orthophosphate values are expected to be less than total phophate since its only one component of total phosphate.
2009 RESULTS: The lowest orthophosphate level was 0mg/L on Big Blue River at 600 N and Garner St. and Duck Creek at Greensboro Pike. The highest level was recorded at 0.6mg/L on Big Blue River at 400 South.
TURBIDITY
Turbidity is the relative clarity of the water and is measured by shining a light through the water column. Turbid water is more cloudy, and is caused by suspended matter including clay, silt, organic and inorganic matter, and algae. Turbid water may be the result of soil erosion, urban runoff, algal blooms, and bottom sediment disturbances caused by boat traffic or abundant bottom feeding fish. When water is turbid, the floating particles absorb heat from the sun, raising water temperature and thus lowering dissolved oxygen levels. The particles can also kill fish and aquatic invertebrates by clogging their gills and smothering their habitat.
We use a transparency tube to determine the turbidity of the river or tributary. We take the transparency reading from the tube (in inches or centimeters) and convert it to NTUs (Nephelometer Turbidity Units) using the chart found in the Hoosier Riverwatch Training Manual Spring 2008.
Indiana's average for turbidity is 36 NTUs.
2009 RESULTS: All of the readings taken in early in the season read less or were equal to 15 NTUs. The highest NTU recorded was 70 on Montgomery Creek at US 40 after a heavy storm.
E. COLI
Escherichia coli is a specific species of fecal coliform bacteria used in Indiana's state water quality standards. Fecal coliform bacteria are found in the feces of warm-blooded animals, including humans, livestock, and waterfowl. These bacteria are naturally present in the digestive tracts of animals, but are rare or absent in unpolluted waters. Fecal coliform bacteria typically enter water by way of combined sewer overflows (CSOs), poor septic systems, and runoff from agricultural feedlots. The bacteria can enter the body through the mouth, nose, eyes, ears, or cuts in the skin.
Some strains of E. coli can lead to illness in humans. While not all strains of E. coli are pathogenic (disease causing) themselves, they occur with other intestinal tract pathogens that may be dangerous to human health. We test for the presence of E. coli as an indicator of fecal contamination.
Indiana's average for E. coli is 645 colonies/100mL.
Indiana's state WQS for total body contact recreation is less than 235 colony forming units (CFUs)/100mL for a single sample.
Sixty eight water samples were collected monthly from 10 sites throughout the watershed starting in April and finishing in October. Once the samples were collected they were taken to the Henry County Health Department and from there, transported to a lab in Indianapolis to determine results.
2009 RESULTS: Only nineteen out of the 68 samples tested lower than 235 CFUs. October E. coli results were the lowest of the monitoring year at all but one monitoring site - Big Blue River at 600 N tests came back at 920 CFUs.
PHYSICAL ASSESSMENTS
Streamflow - Streamflow is usually recorded by the U.S. Geological Survey (USGS) at stream gaging stations across the United States. The only USGS gage in the Big Blue River watershed is located on the Big Blue in Carthage (http://waterdata.usgs.gov/nwis/nwisman/?site_no=03361000&agency_cd=USGS). Streamflow is also known as discharge and it is the volume of water flowing in the stream at a certain location per second. It influences other physical, chemical, and biological factors. For example, when a large accumulation of snow melts, it carries sediment and nutrients off the land into the stream. High discharge rates indicates recent rainfall or snowmelt events, whereas low discharge rates indicates drought conditions. Low discharge affects aquatic life and water quality. Streamflow is calculated by multiplying the average width, depth, and velocity of the stream.
CQHEI (Citizens Qualitative Habitat Evaluation Index) - This evaluation provides a measurement of stream habitat and riparian health in relationship to fish and macroinvertebrates. It uses a score that can be compared over time or between two different sites. The maximum score is 114. The higher the score, the better the habitat. Categories measured are: Substrate (Bottom-type), Fish Cover (Hiding Places), Stream Shape and Human Alterations, Stream Forests and Wetlands (Riparian Areas) & Erosion, Depth & Velocity, and Riffles/Runs.
BIOLOGICAL ASSESSMENT (benthic macroinvertebrates)
Volunteers sample the aquatic organisms living in the stream once a year because most of them spend a large part of their life cycle in the same jpart of a stream, clinging to objects so they are not swept away with the water's current. They're relatively easy to sample, abundant and can easily be collected and identified by trained volunteers. They reflect a streams physical and chemical condition over time. There are organisms that can tolerate pollution and those that are pollution-sensitive. Monitoring the numbers and types of organisms at the same site year after year and comparing what organisms are found may indicate the effects of human activity on the stream.
(Summaries of the chemical parameters and assessments were taken from Hoosier Riverwatch Training Manual, Spring 2008.)
updated: April 19, 2010