2025 3 18 Packet 2

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ORDINANCE NO. 1138 
Page 3 of 19 
 
requirements of the National Pollution Discharge Elimination System permit (NPDES) 
and applicable regulations, 40 CFR § 122 as applicable for stormwater discharges. 
(7) Borrow Pit is an excavation from which erodible material (typically soil) is removed to 
be fill for another site. There is no processing or separation of erodible material 
conducted at the site. Given the nature of activity and pollutants present at such 
excavation, a borrow pit is considered a construction activity. 
(8) Buffer Zone or Water Quality Riparian Buffer is a permanent strip of natural perennial 
vegetation, adjacent to a stream, river, wetland, pond, or lake that contains dense 
vegetation made up of grass, shrubs, and/or trees. The purpose of a water quality riparian 
buffer is to maintain existing water quality by minimizing risk of any potential sediments, 
nutrients or other pollutants reaching adjacent surface waters and to further prevent 
negative water quality impacts by providing canopy over adjacent waters.  
(9) Channel means a natural or artificial watercourse with a definite bed and banks that 
conducts continuously or periodically flowing water. 
(10) Clearing refers to removal of vegetation and disturbance of soil prior to grading or 
excavation in anticipation of construction activities. Clearing may also refer to wide area 
land disturbance in anticipation of non-construction activities. Clearing, grading, and 
excavation do not refer to clearing of vegetation along existing or new roadways, 
highways, dams, or power lines for sight distance or other maintenance and/or safety 
concerns, or cold planing, milling, and/or removal of concrete and/or bituminous asphalt 
roadway pavement surfaces. The clearing of land for agricultural purposes is exempt 
from federal stormwater NPDES permitting in accordance with Section 401(1)(1) of the 
1987 Water Quality Act and state stormwater NPDES permitting in accordance with the 
Tennessee Water Quality Control Act of 1977 (T.C.A. 69-3-101 et seq.). 
(11) Commencement of construction: the initial disturbance of soils associated with 
clearing, grading, excavating or other construction activities. 
(12) Common plan of development or sale is broadly defined as any announcement or 
documentation (including a sign, public notice or hearing, sales pitch, advertisement, 
drawing, permit application, zoning request, computer design, etc.) or physical 
demarcation (including boundary signs, lot stakes, surveyor markings, etc.) indicating 
construction activities may occur on a specific plot. A common plan of development or 
sale identifies a situation in which multiple areas of disturbance are occurring on 
contiguous areas. This applies because the activities may take place at different times, on 
different schedules, by different operators. 
(13) Control measure refers to any Best Management Practice (BMP) or other method 
used to prevent or reduce the discharge of pollutants to waters of the state. 
(14) CWA means the Clean Water Act of 1977 or the Federal Water Pollution Control 
Act (33 U.S.C. 1251, et seq.) 
(15) Design storm is a storm event as defined by Precipitation-Frequency Atlas of the 
United States. Atlas 14. V olume 2. Version 3.0. U.S. Department of Commerce. National 
Oceanic and Atmospheric Administration (NOAA), National Weather Service, 
Hydrometeorological Design Studies Center, Silver Springs, Maryland or its digital 
product equivalent.  The estimated design rainfall amounts, for any return period interval 
(i.e., 1,-yr, 2-yr, 5-yr, 25-yr, etc.,) in terms of either  depths or intensities for any duration, 
can be found by accessing the data available at 
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html . The C
ity of Athens requires 
Stormwater Control Measures (S CM) to be designed to accommodate Design Storm 
Events through the 100-year event; design storm depths/intensities shall be values 
provided for TN Station ATHENS (40-0284). 
(16) Di scharge or discharge of a pollutant refers to the addition of pollutants to waters 
from a source, either point or non-point in nature. 
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