Equipment Research

The Upper South Platte Watershed is subject to many different sources and types of pollution. According to the Colorado Department of Public Health & Environment (CDPHE), the two primary causes of non-point source pollution in the Upper South Platte Watershed are city drainage and sedimentation.

Chemical testing measures the concentration of dissolved and suspended substances in the water. These substances may be naturally occurring or introduced pollutants. Chemical testing only reveals a snapshot of what is occurring in the watershed at the time that the testing occurs. From this information, it can be determined if there are any pollutants such as fertilizers, sewage, drainage, etc., introduced into the water. It can also determine the natural constituents of the watershed such as oxygen levels, alkalinity, turbidity, etc. CDPHE utilizes LaMotte water quality testing kits.

Upper South Platte Watershed Common Sources of Chemical Pollutants

• Farmland/Residential Lawns – higher turbidity, nitrates, phosphates
• Forest harvest – higher turbidity
• Pasture – increased bacteria, turbidity, nitrates, phosphates, etc.
• Mining – decreased pH, reduced alkalinity, increased iron, and other metals
• Industrial discharge - increased toxins and pH 
• Septic systems failure – increased bacteria, nitrates, phosphates, etc.
• Construction sites – increased turbidity and toxins
• Urban runoff – increased turbidity, nitrates, and phosphates

Sampling Equipment - Physical Parameters

• Hip boots/waders
• Armored thermometer (Celsius)
• Aluminum meter stick
• 50-meter measuring tape
• Wooden stakes
• Compass
• Hammer or mallet for driving stakes
• Cord or string
• Float (apple or orange or tennis ball)
• Colored clothespins
• Stopwatch
• Calculator
• Colorado plant and aquatic field guides
• Copies of datasheets, stream walk papers, pencils and clipboards
• Topographical map of the watershed

Sampling Equipment - Chemical Parameters

• Iron test kit
• pH test kit
• Dissolved oxygen test kit
• Total Hardness test kit
• Turbidity test kit
• Nitrates test kit
• Alkalinity test kit
• Leak proof container for chemical wastes and a funnel
• Distilled water
• First Aid Kit and eyewash kit
• Safety goggles
• Nitrile gloves
• Copies of chemical data sheets, clipboards, and pencils

LaMotte Test Kit

Colorimetric - pH, Nitrate, Iron

Colorimetric tests work on Beer’s Law; the higher the concentration of a substance, the darker the color developed in the test, so more light is absorbed by the sample. In other words, when the indicator solution is added to the test sample, it will change color. Determining the concentration of what is being tested for in the sample. For example, the pH test uses an indicator that changes color with changes in the concentration of hydrogen ions, or the acidity of the solution.

Turbidimetric – Turbidity

In this test, no reagent is added to the water sample being tested, instead a turbidity standard is created by adding turbidity reagent to the distilled (or tap) water sample until it matches the turbidity of the sample. If the sample is too turbid to see the black dot at the 25 ml level, it must be diluted and the results calculated accordingly. For example, dilute 1 part sample to 1 part distilled water, multiply the results by 2; 1 part sample with 3 parts distilled water, multiply the results by 4.

Titrimetric - Dissolved Oxygen, Hardness, Alkalinity

The test sample is first treated with an indicator, and then a standard titrant is added until a color change indicates a completed reaction. This method is used to determine the concentration of a substance in a sample solution. LaMotte recommends the direct reading titrator (DRT) or dropper pipette (drop count) method. In the first, the recordable results are read directly from the scale of the DRT, and in the second, the number of drops used are counted and multiplied by a given number to obtain the recordable results.

Sampling Practices

CDPHE strives for quality assurance and quality control. The same chosen watershed location should be monitored at least twice per year using the Freshwater Acceptance Levels for Chemical Parameters. According to LaMotte's instructions, to increase consistency, it is imperative to follow the guidelines below:

• Use the same test kits and the same methods each time
• Hold dropper bottles vertically (upside down) to dispense liquid; one drop at a time
• Fill and use direct reading titrators according to manufacturer directions
• Rinse glassware 3 times with the sample water prior to filling for test
• Rinse glassware 3 times with distilled water after each test. All post-test rinse water should go into the chemical waste bottle, NOT into the stream
• Collect water for all chemistry tests during the same time period
• Conduct the same test at least twice using the same kit 
• Conduct a third test if results do not agree
• Always record data 

To get an accurate picture of water quality, sampling has to be performed on a regular basis over a period of years. This gives a broad view of the watershed which will weed out seasonal variations from long-term changes. 

The results of many chemical tests can indicate that there is an immediate problem. By sampling several sites upstream from the initial test site, the source of the pollution can be found. Depending on the chemical test performed, the source may be point or non-point.