Several of the Friends of Peachtree Hills Park have been certified by Georgia Adopt-A-Stream (AAS), part of the Waters
hed Protection Branch of the Georgia Environmental Protection Division, to monitor a tributary of Peachtree Creek that runs through our park. Ron Loines is our resident “creek geek” conducting chemical, bacterial, and visual monitoring and reporting the results on the Georgia Adopt-A-Stream web site.
Visit the web site to see the results of our monitoring and learn about the health of our creek and watershed. Our creek is in the Upper Chattahoochie watershed and is identified by site ID 2033. This guide below helps you interpret the information we post on the AAS site.
Chemical monitoring involves testing temperature (air and water), conductivity, pH, and dissolved oxygen. Similar to results of lab tests in people, measurements that are way out of normal range are reported for immediate action. Otherwise it’s generally more useful to look at trends over a period of several months to take early action before a big problem arises.
| Measurement | Normal for our area | What the results mean |
|---|---|---|
| Temperature (air and water) | N/A | Rise in water temperature could mean “thermal” pollution |
| pH | 6-8 is considered normal. Our creek is generally between 6.5 and 7.0 | Is a measure of hydrogen ions, but think of pH as how acidic (low pH) or alkaline (high pH) something is. pH is measured on a 14-point scale where 7 is neutral. Distilled water, for example, has a pH of 7.0 |
| Conductivity | Typically 50-1500 with ours usually between 200 to 260 | Conductivity measures the presence of ions or the number of dissolved inorganic compounds (also known as salts). There is no overall norm as conductivity is affected by geology. Limestone and clay increase conductivity while concentrations of granite lower conductivity. |
| Dissolved Oxygen | Average of 5 milligrams/liter | Dissolved oxygen (DO2) is an indicator of a stream’s ability to support aquatic life. Things that increase DO2 include plant life, barometric pressure and turbulence. DO2 decreases with warmer temperatures, slow, still, or deep water, or an overload of decaying material. |
Bacterial monitoring looks for the presence of E. coli, a fecal coliform (colony-forming) bacteria that lives harmlessly in the intestines of mammals. E. coli discovered in our creek is directly attributed to the waste of animals. So things like sewage spills
, failing septic systems, leaky pipes, and storm run-off cause an increase in the levels of E. coli in a water way.
E. coli is measured in terms of colony forming units (CFU) per 100 milliliters of water. Ordinarily E. coli is harmless but poses a human (and pet) risk at high levels. Counts equal to or greater than 1000 cfu/100 ml warrant immediate action and are reported to Watershed Management.
The table below shows the recommended E. coli standards for recreational waters. The levels shown correspond to an acceptable risk level of 8 people out of 1000 getting sick.
| Designated swimming area | Moderate swimming area | Light swimming area | Infrequent swimming area | |
|---|---|---|---|---|
| E coli (cfu/100ml) | <235 | <298 | <410 | <576 |
Visual observation
In addition to our chemical and bacterial monitoring, we also report changes in the overall appearance and characteristics of the creek and the creek bank. Visual inspection includes things like clarity or turbidity of the water, excess amounts of silt or organic matter, erosion or damage to the creek banks, and so forth.