What is the largest wastewater treatment plant in Tennessee?

Metro Central Wastewater Treatment Plant in Nashville, treating an average of 103.22 MGD under NPDES permit TNL020575. Moccasin Bend Wastewater Treatment Plant in Chattanooga is second at 50.56 MGD.

How much wastewater do Tennessee’s largest plants treat?

The 50 largest plants treat 362 MGD combined, 90% of the flow reported by all 243 publicly owned plants in Tennessee.

How is plant size measured?

By reported average daily flow in million gallons per day (MGD) from EPA discharge monitoring reports, the standard measure of a plant’s size. Design capacity, the flow a plant is permitted to treat, is usually higher and is shown on each profile.

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The 50 largest wastewater treatment plants in Tennessee

Name: Largest wastewater treatment plants in Tennessee
Creator: Klarifi
License: https://klarifi.io/terms-of-service

Ranked by average flow · 362 MGD combined · 90% of the state's reported flow

Metro Central Wastewater Treatment Plant in Nashville is the largest publicly owned wastewater treatment plant in Tennessee by reported average flow, treating about 103.22 million gallons per day. The 50 plants below treat 362 MGD between them, 90% of the flow reported by all 243 plants in the state, and serve about 2,270,013 people. Every plant links to its profile with permit and compliance data. Treatment technology is shown with a free Klarifi account.

All plants in Tennessee →The 50 largest US plants →Tennessee NPDES permits →

The 50 largest publicly owned wastewater treatment plants in Tennessee by average flow (MGD), with population served, NPDES permit, expiry and three-year violation count.
#	Facility	City	Avg flow (MGD)	Population	NPDES permit	Expires	Violations (3y)
1	Metro Central Wastewater Treatment Plant	Nashville	103.22	649,235	TNL020575	Dec 2030	63
2	Moccasin Bend Wastewater Treatment Plant	Chattanooga	50.56	262,562	TNR053775	Jun 2030	52
3	Whites Creek Wastewater Treatment Plant	Nashville	32.64	54,671	TN0024970	Oct 2025	40
4	Nashville Dry Creek STP	Madison	16.24	201,478	TN0020648	Oct 2025	34
5	City Of Cookeville Department Of Water Quality Control (wwtp)	Cookeville	10.75	38,338	TN0024198	Jun 2027	27
6	City Of Franklin Wastewater Treatment Plant	Franklin	9.77	80,675	TN0028827	Dec 2026	44
7	First U.D. Knox Co.-Turkey Cr	Knoxville	8.49	104,525	TN0023353	Apr 2027	23
8	Cleveland Utilities Wastewater Treatment Plant	Charleston	8.48	65,814	TN0024121	Apr 2027	44
9	Oakland - Mechanical WWTP	Oakland	8.18	8,135	TN0077836	Dec 2027	35
10	Hallsdale-Powell U.D.-Melton Hill Lk	Knoxville	6.35	81,175	TN0078905	Sep 2028	44
11	Johnson City STP	Johnson City	5.94	66,934	TN0024244	Sep 2026	18
12	Harpeth Valley Utility District STP	Nashville	5.88	27,220	TN0074748	Feb 2030	4
13	City Of Columbia Wastewater Treatment Plant	Columbia	5.33	39,515	TN0056103	Oct 2028	68
14	Turkey Creek WWTP (morristown Stp)	Morristown	5.12	38,163	TN0023507	Oct 2029	22
15	Sevierville (mccroskey Island) STP	Sevierville	4.74	17,185	TN0063959	Apr 2030	115
16	Oak Ridge STP	Oak Ridge	4.37	29,124	TN0024155	Dec 2028	35
17	West Knox Ud Melton Lake WWTP	Knoxville	4.07	55,529	TN0080721	Mar 2028	13
18	Dyersburg STP	Dyersburg	3.87	18,727	TN0023477	Dec 2027	20
19	City Of Spring Hill STP	Spring Hill	3.83	41,797	TN0075868	Dec 2028	41
20	Collierville Northwest STP	Collierville	3.64	25,298	TN0078841	Jan 2028	4
21	Knob Creek Waste Water Plant	Johnson City	3.26	14,154	TN0024236	Sep 2026	15
22	Shelbyville Wastewater Treatment Plant	Shelbyville	3.22	21,841	TN0024180	Jan 2029	21
23	Humboldt Utilities Authority	Humboldt	3.13	8,145	TN0062588	Aug 2027	7
24	Denzil Bowman Wastewater Treatment Plant (greeneville Stp)	Greeneville	3.1	14,938	TN0021229	Oct 2030	30
25	Tullahoma STP	Tullahoma	2.98	19,982	TN0023469	Jul 2027	6
26	Dickson STP	Dickson	2.91	20,986	TN0066958	Dec 2026	21
27	Crossville STP	Crossville	2.81	14,372	TN0024996	Dec 2026	26
28	Union City STP Aka A.L. Strub Wastewater Treatment Plant	Union City	2.71	10,952	TN0021580	Oct 2030	1
29	Jackson Energy Auth- Middle Fk	Jackson	2.58	26,036	TN0075876	May 2027	6
30	Manchester STP	Manchester	2.4	10,896	TN0025038	Feb 2029	39
31	Gatlinburg STP	Gatlinburg	2.29	3,944	TN0020117	Aug 2030	17
32	Clinton WWTP #1	Clinton	2.1	11,062	TN0026506	May 2028	3
33	Lewisburg STP	Lewisburg	2.07	12,150	TN0022888	May 2028	22
34	Elizabethton WWTP	Elizabethton	1.93	13,568	TN0023515	Aug 2031	18
35	City Of Pulaski Wastewater Treatment Plant	Pulaski	1.93	7,614	TN0021687	Oct 2027	2
36	Lenoir City STP	Lenoir City	1.78	17,047	TN0020494	Jul 2031	11
37	Smithville STP	Smithville	1.73	4,781	TN0065358	Sep 2027	1
38	Newport Utilities Board Wastewater Treatment Plant	Newport	1.65	6,865	TN0020702	Mar 2030	10
39	Covington Wastewater Treatment Plant	Covington	1.63	8,863	TN0020982	Mar 2029	1
40	Mcminnville Wastewater Plant	Mcminnville	1.63	13,695	TN0023591	Jan 2028	5
41	Town Of Collierville	Collierville	1.48	25,298	TN0057461	Dec 2028	5
42	City Of Savannah	Savannah	1.44	6,934	TN0061565	Sep 2028	23
43	Camden Hcr Lagoon And Spray Irrigation	Camden	1.42	3,588	TN0064611	Nov 2028	79
44	Arlington STP	Arlington	1.42	11,715	TN0078603	Nov 2027	94
45	Ashland City Wastewater Treatment Facility	Ashland City	1.37	—	TN0082252	May 2030	2
46	Martin STP	Martin	1.32	10,585	TN0062545	May 2030	21
47	Town Of Livingston	Livingston	1.18	4,058	TN0021873	Jun 2030	18
48	City Of Portland 2021 Gravity Sewer Interceptor	Portland	1.18	13,088	TN0021865	Aug 2029	217
49	Munford Sewer Department Lagoon	Munford	1.15	18,918	TN0062499	Dec 2030	10
50	Lexington Utilities- Waste Water Treatment Plant	Lexington	1.13	7,838	TN0024341	Oct 2028	7

Treatment technology for each plant is shown with a free Klarifi account. Create one →

Largest plants in Tennessee: questions

Sources and methodology

Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.

Data refreshed October 26, 2026.

Wastewater terms: WWTP · POTW · MGD · NPDES permit · Equalization tank · Centrate · all terms

Cite this page

Journalists, researchers and educators are welcome to quote these figures. Please credit Klarifi as the source and link to this page.

Klarifi. “Largest wastewater treatment plants in Tennessee (2026).” Updated October 26, 2026. https://klarifi.io/facilities/tennessee/largest

Need a custom cut of the data for a state, a county or a list of plants? Email info@klarifi.io.

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