Chemistry Analysis"Chemistry"
The Chemistry Analysis study assesses the health of Arcade Creek, chiefly the ability of the creek to support life and maintain a healthy ecosystem. Chemists begin their work by collecting two separate water samples (pool and riffle) from their site on the creek each month. They then return to the lab to perform several simple tests that assess the levels of various chemicals found in the creek. Some of these tests include:
Dissolved Oxygen (DO): This measure of atmospheric oxygen in the water indicates whether a healthy amount of photosynthesis occurs at the creek. All figures above 9.5 mg/L are considered healthy.
pH: The Power of Hydrogen—or the ratio of hydrogen ions to hydroxide ions—which indicate whether a sample is acidic or basic on the scale of 0 to 14. When pH becomes too acidic, some harmful compounds may be induced to dissolve. pH should range from 6.5 to 8.5.
Alkalinity: This measure of the strength of acid-neutralizing buffers indicates how well the creek can guard against the dire pH shifts that would harm fish and other complex organisms.
Phosphates: When present in small quantities, phosphates are necessary for plant life. However, an excessive amount of phosphates will encourage more plant growth than the system can bear and other organisms will die for lack of oxygen.
Nitrates: Much like phosphates, nitrates are needed by plants but harmful in high quantities for the algal bloom they encourage. Nitrates can also contaminate drinking water.
Ammonia: This comes about as a result of protein hydrolysis. Ammonia is toxic to gilled organisms, especially when pH is high.
Hardness: This measures the amount of calcium ions in the creek’s water. Ideally, a low amount of calcium ions should effectively prevent the ions of heavy metals such as copper from binding to the gills of certain organisms. Measurements in hardness often fluctuate because of human disturbance.
