--- title: Chemical monitoring description: "# **Chemical monitoring (common tests)** **Category: Watershed 101** ## **Common Chemical Tests** ## **Alkalinity** Alkalinity measures the buffering capacity of the stream, or its ability to resist changes in pH. Carbonate and bicarbonate are the most influential compounds in determining…" url: "https://aml-connect.org/aml-knowledge-base/chemical-monitoring/" updated: "2026-09-30" category: Watershed Tools and Methods / Water Monitoring / Chemical Monitoring --- # Chemical monitoring # **Chemical monitoring (common tests)** **Category: Watershed 101** ## **Common Chemical Tests** ## **Alkalinity** Alkalinity measures the buffering capacity of the stream, or its ability to resist changes in pH. Carbonate and bicarbonate are the most influential compounds in determining alkalinity. Streams with low alkalinity levels are not able to resist pH changes. This leads to drastic effects on the aquatic life if acid rain falls into the stream or it is affected by AMD. Stream that naturally run through limestone or are fed by groundwater filtered by limestone have much higher natural alkalinity levels. The picture below is an example of an alkalinity test kit. As with most HACH tests the directions are very easy to read and follow. The tests for alkalinity and acidity are very similar. The main difference lies in the reagent used to titrate the sample to a color change. Or, in English, the chemical that is added (drop wise) to the sample until it changes color as directed in the instructions. HACH Company provides a catalogue of chemical water testing kits and supplies http://www.hach.com/ Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators the were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed. ## **Acidity** Acidity and pH, although having similarities, should not be confused with each other. pH is a measure of the concentration of free hydrogen ions. This actual concentration of hydrogen ions is a component (often dominant) part of acidity, yet other positively charged ions (cations) also contribute to the acidity of water. Total acidity measures the acidity of the water including both the pH and the other sources of acidity. Above is a picture of a total acidity test kit from HACH used for field testing. This is a common test kit that is easy to use and read. The directions included with the test are relatively simple and easy to read. This kit will test both free and total acidity. Free acidity will measure the amount of acidity in the water and is reported as the equivalent amount of calcium carbonate (CaCO3) that would be needed for neutralization of the acidity. Total acidity includes calcium carbonate, hydrogen and all other sources of acidity in the water. HACH Company provides a catalogue of chemical water testing kits and supplies Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators the were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed. ## **TDS** Total Dissolved Solids (TDS) refers to the ions and other particles dissolved in the water that you can't see. Be careful not to confuse this test with conductivity, which measures the electrical conductance of water. The two are closely related, but no the same. The major components of TDS are bicarbonate, calcium, sulfate, hydrogen, silica, chlorine, magnesium, sodium, potassium, nitrogen, and phosphorus. It is essential to maintain a constant level of these solids. For example, a sudden increase is salt from brine leakage of a mineral extraction pond can have a devastating effect on the aquatic life. Streams containing flow primarily from groundwater have a high TDS level as minerals leach into the water as it filters through the rocks. Storm water is usually low in TDS. Dissolved Oxygen (DO) Dissolved Oxygen (DO) is absolutely essential for the health of organisms in aquatic environments. The macro invertebrates depend on this to breathe, as they cannot produce their own oxygen. It usually ranges from 0 to 20 g/L, with higher values indicating better water quality. Colder water typically has a higher DO capacity than warmer water. Once the level of DO has been determined, as well as the temperature, you can use a percent saturation chart to find out if your stream has all the oxygen it can hold. Though a level of 13mg/L DO might not sound high, it may mean that your stream is at 100% saturation: the best level possible. Lower saturation levels may be due to pollution affects. . ## **·E** This picture is an example of a dissolved oxygen test kit from HACH. These are relatively easy to use and accurate. Clear directions are included with the kit. It is very important when using this test kit, however, to be sure that no air bubbles are introduced to the sample. Any air bubbles that are in the sample or that enter the sample during the testing may alter the results. Dissolved oxygen meters are also commonly used for testing. These meters are very similar to pH meters, a wand is inserted into the water after the meter has been calibrated to compensate for temperature and altitude. The dissolved oxygen content is then recorded from the readout. HACH Company provides a catalogue of chemical water testing kits and supplies Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators that were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed. pH pH is a measure of the concentration of free hydrogen I water. For an in depth explanation of water pH is, see Acids, Bases and pH. The pH of water is extremely critical to the aquatic life; only a small range of variation will support life. Most streams in PA have a pH between 6.5 and 8.5, except for those affected by acid pollution. Rocks and soils containing calcium carbonate act as buffers and raise pH, causing groundwater to be less acidic than rainwater or storm water. Rainwater is usually around pH of 5.6, acid precipitation, however, has a pH of 4.5 or lower. A lower pH is normally found in streams during the winter and spring due to the high amounts of rain and snow melts. Summer and fall usually have lower pH levels, as groundwater is the major source during these seasons.'P This pH test kit is very easy to use. Two samples of water are compared, a clear one placed behind a colored disk called a color wheel, and a second sample to which a pH indicator is added. The pH is determined by matching the color of the altered sample to the sample behind the color disk after so many drops of indicator are added. pH may also be measured using a meter. pH meters are relatively common and inexpensive. It is important to make sure that any pH meter is properly calibrated before use and that the electrodes are stored properly to prevent dehydration of the membrane. To use a pH meter, simply place the test electrode into the water and watch the readout. Meters should come with directions for proper calibration and storage as each differs between specific meters. HACH Company provides a catalogue of chemical water testing kits and supplies Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators the were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed\ ## **Aluminum** Some information compiled using "Impacts of Mine Drainage on Aquatic Life, Water Uses, and Man-made Structures" http://www.dep.state.pa.us/dep/deputate/minres/districts/CMDP/chap04.htm l Aluminum is one of the most abundant elements in the earth's crust and occurs in many rocks and ores, but never as a pure metal. Aluminum combines with organic and inorganic ions and can be found in several forms. Aluminum can change form but it cannot be destroyed. Under natural, pristine conditions, aluminum rarely occurs in water at concentrations greater than a few tenths of a milligram per liter. Waters with high concentrations of aluminum, often seen flowing bright white, are toxic to aquatic life due to lowered pH levels. Increased aluminum concentrations can be related to abandoned mine discharges, acid precipitation and the natural breakdown of clays. When aluminum precipitates (drops) out it coats channel rocks, eventually destroying the streams ecosystem. Aluminum precipitate can be directly toxic to fish and macroinvertebrates. Aluminum affects fish by accumulating on their gills thereby affecting their breathing. At a combined pH of less than 5.5 and a dissolved aluminum concentration greater than 0.5 mg/L, almost all fish and macros will be eliminated. Of the three major metals found in AMD, aluminum has the most severe effect on aquatic life. Aluminum samples are taken using standard procedures and analyzed in a lab. Results are recorded in mg/L and the State Drinking Water Limit is.2 mg/L. ## **Manganese** Magnesium, a common metallic metal found in the earth's crust, is of particular importance in water pollution. Manganese can be found in a variety of forms and can be present in a variety of compounds and complexes with organic compounds. Like iron, it's a naturally occurring metal that often becomes a problem after local mining activities cease. Samples are analyzed for magnesium in a lab using standard procedures. Results are recorded in mg/L and compared to the State Drinking Water Standard, which is 0.05mg/L. Magnesium precipitates out of water when it comes in contact with oxygen, turning the channel black, however the pH must raise above 10 before it will precipitate out. The affects of elevated levels of manganese on aquatic life is difficult to determine because it is often associated with other naturally occurring, yet detrimental metals. Research has concluded that the less common precipitated form of manganese is more toxic then the dissolved form. As it settles to the channel bottom it, like iron and aluminum, destroys the aquatic ecosystem by covering rocks and filling cracks where insects live and fish lay their eggs, lowering macroinvertebrate diversity. ## **Nitrogen** High nitrogen levels are usually due to fertilizer runoff from neighboring farms and golf courses or sewage treatment runoff. The excess of what is usually a growth-limiting nutrient causes adverse effects in the algal populations. Algal blooms develop turning the water a soupy green. These blooms rapidly use up the dissolved oxygen in the water, stressing aquatic organisms and fish that depend on the dissolved oxygen to survive. It is common to find some species almost totally destroyed after an algal bloom. The population of algal weeds may also increase, clogging waterways and making boating difficult. High nitrogen levels can also lead to "brown blood disease" in fish as well as being harmful to infants under 3 months of age. Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators the were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed. ## **Phosphorus** Phosphorus has many of the same effects as nitrogen. It can spark algal blooms as well as increase algal weed populations. Fertilizer runoff, sewage treatment run off, or detergents and cleaners can cause excess phosphorus. Phosphorus has the additional danger of being able to settle into the sediment of the lake or stream to be re-suspended when water currents increase. Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators the were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed. ## **Sulfates** Sulfates enter a stream by erosion. Areas with high concentrations of gypsum or shale are prone to high sulfate concentrations. AMD also adds large amounts of sulfates to the water. Iron pyrite (FeS2), a large element of AMD, yields both ferrous iron and sulfate when flowing into streams. Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators the were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed. ## **Turbidity** Turbidity refers to the dissolved solids in the water, which you can see. Cloudy water is said to have a high turbidity level. Common causes of turbidity are erosion, runoff, waste discharge and algal growth. Turbidity is usually determined using a black and white disk, lowered into the water until the white is no longer visible. The depth at which the disk can no longer be seen is indicative of the turbidity. Other tests, including and/or in addition to those described above, may be appropriate for the watershed in your area. The indicators the were chosen as points of study while making your monitoring plan are a good way to decide what tests need to be performed. Turbidity from Water on the Web http://wow.nrri.umn.edu/wow/under/parameters/turbidity.htm l Turbidity from Water SHEDDS http://h2osparc.wq.ncsu.edu/info/turbid.htm l Water Quality Monitoring: Turbidity from Friends of Five Creeks http://www.fivecreeks.org/monitor/turbidity.htm l USGS Water Resources--Office of Water Quality National Field Manual Chapter 6.7 Turbidity (pdf) http://water.usgs.gov/owq/FieldManual/Chapter6/Section6.7.pdf **Sources/Links (as provided in the source text):** - http://www.hach.com/ - http://www.dep.state.pa.us/dep/deputate/minres/districts/CMDP/chap04.htm - http://wow.nrri.umn.edu/wow/under/parameters/turbidity.htm - http://h2osparc.wq.ncsu.edu/info/turbid.htm - http://www.fivecreeks.org/monitor/turbidity.htm - http://water.usgs.gov/owq/FieldManual/Chapter6/Section6.7.pdf **AML Wiki — KB-ready Drafts****Service Pack SP3: Water Monitoring (Batch 2 — Atomized Subpages)** Exact content with light grammar/format cleanup only | Date: 2025-12-31 Usage: Copy/paste each article into the Knowledge Base as its own entry. 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