2025 3 10 Work Session Packet 1

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ORDINANCE NO. 1138 
Page 11 of 19 
 
(13) Notice of Termination (NOT) - The operator shall provide the City with a copy of 
the NOT once it is issued by TDEC. 
14-504. Permanent stormwater management: D esign and Construction. 
(1) In order to comply with the City’s permanent stormwater standards for new development 
and redevelopment projects, operators shall design and install SCMs as established by 
Tennessee Rule 0400-40-10-.04 and comply with other requirements of Tennessee Rule 
0400-40-10-.04. 
(2) The Post Construction/Permanent water quality design storm is a 1-year, 24-hour storm 
event. Actual project WQTV requirements shall be based on the proposed permanent 
SCM treatment type as outlined in 4.2.5.2 of the Small MS4 General Permit NPDES 
Permit TNS000000.   
(3) SCMs must be designed to provide full treatment capacity within 72 hours following the 
end of the preceding rain event for the life of the new development or redevelopment 
project. The operator may use any design manuals approved as part of the City’s BMP 
Manual.  
(4) Total suspended solids (TSS) removal rate shall be the City’s recognized metric for the 
reduction of pollutants in stormwater effluent. Design TSS removal rates for approved 
MTDs shall be established by a 3
rd party verification or certification program recognized 
by the City such as those of NJDEP and WSDOE. 
(5) Post Construction/permanent water quantity SCMs shall be designed to attenuate post-
construction peak flows from the 2-year 24-hour event through the 100-year 24-hour 
storm event to equal or less than pre-development peak flows for all new development 
and redevelopment projects.  
(6) W
ater Quality Riparian Buffers - Post Construction/Permanent water quality riparian 
buffers shall be those buffers defined in 14-502 above and shall meet the requirements 
described in this ordinance.  The criteria for the width of the post construction/permanent 
buffer zone can be established on an average width basis at a project, as long as the 
minimum width of the buffer zone is more than the required minimum width at any 
measured location. If the new development or redevelopment site encompasses both sides 
of a stream, buffer averaging can be applied to both sides, but must be applied 
independently. Water quality riparian buffer widths are measured from the top of bank 
also referred to as the “ordinary high-water mark.” Stormwater discharges should enter 
the post construction/permanent water quality riparian buffer as sheet flow, not as 
concentrated flow, where site conditions allow. 
(7) P
ost Construction/Permanent buffers for waters with available parameters for siltation o r    
habitat alteration or unassessed waters: 
(a) Average buffer width: 30 feet. 
(b) Minimum buffer width: 15 feet. 
 
(8) Post Construction/Permanent buffers for Exceptional Tennessee Waters or waters with 
unavailable parameters for siltation or habitat alteration: 
(a) Average buffer width: 60 feet. 
(b) Minimum buffer width: 30 feet 
 
(9) The designer/operator must comply with the vegetation requirements and the permissible 
land uses set forth for buffers in the MS4 permit. 
14-505. Permanent Stormwater Management: S
 CM Acceptance, Maintenance and 
Inspection.  
(1) All applicants are required to submit actual as built plans for any structures located on-
site within 90 days after final construction is completed.  The plan must show the final 
design specifications for all stormwater management facilities and must be sealed by a 
registered professional engineer licensed to practice in Tennessee. A certification by the 
design engineer certifying that SCM’s will function within original design parameters as 
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