How many wastewater treatment plants are there in Minnesota?

Klarifi tracks 460 publicly owned wastewater treatment plants in Minnesota with a combined average flow of 341 million gallons per day, serving about 3,937,403 residents. 28 of them treat more than 1 MGD and 5 more than 10 MGD.

What is the largest wastewater treatment plant in Minnesota?

Met Council Metropolitan WWTP in Saint Paul is the largest plant in Minnesota by average flow, treating about 180 MGD.

What treatment technologies are common in Minnesota?

341 of Minnesota's plants use lagoon systems and 106 have biogas or anaerobic digestion infrastructure, based on Klarifi's aerial imagery review.

How many NPDES permits in Minnesota are up for renewal?

27 permits held by Minnesota plants expire in 2026 and 35 in 2027. Renewals typically bring new limits and trigger upgrade projects.

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Wastewater Treatment Plants in Minnesota

Name: Wastewater treatment plants in Minnesota
Creator: Klarifi
License: https://klarifi.io/terms-of-service

460 facilities · 341 MGD combined flow

Klarifi tracks 460 publicly owned wastewater treatment plants in Minnesota with a combined average flow of 341 MGD, serving about 3,937,403 residents. 28 plants treat more than 1 MGD and 5 more than 10 MGD; 341 use lagoon systems and 106 have digesters or biogas infrastructure. The largest is Met Council Metropolitan WWTP in Saint Paul at 180 MGD. 27 NPDES permits expire this year and 35 next year.

Every plant below links to a profile with average and design flow, treatment technology, the NPDES permit and its expiry, a three-year compliance snapshot and the capital projects planned in its city. Showing facilities 1–200 of 460 by average flow — browse the rest with the page links below.

460 plant locations in Minnesota; dot size follows average flow.

NPDES permits and renewals in Minnesota

Every plant discharges under an NPDES permit that is renewed every five years, usually with tighter limits. The renewal year is the year a plant budgets for upgrades.

All NPDES permits in Minnesota →27 permits expiring in 2026 →35 permits expiring in 2027 →234 permits expiring in 2028 →Find plants near you on the map →

Largest wastewater treatment plants in Minnesota

The 25 largest publicly owned wastewater treatment plants in Minnesota by average flow, with NPDES permit, expiry, treatment technology and three-year violation count. Source: EPA ICIS-NPDES via Klarifi.
Facility	City	Avg flow (MGD)	Design (MGD)	NPDES permit	Expires	Technology	Violations (3y)
Met Council Metropolitan WWTP	Saint Paul	180	—	MNL029815	Dec 2030	Biogas silos	0
Blue Lake Wastewater Treatment Plant	Shakopee	26.54	42	MN0029882	Sep 2029	Biogas silos, Biogas balloons	0
Seneca Wastewater Treatment Plant	Eagan	20.92	38	MN0030007	Nov 2028	Clarifiers	6
Met Council - Empire WWTP	Farmington	12.05	—	MNL045845	Dec 2030	Clarifiers, Uncovered lagoons, Biogas silos, Biogas balloons	0
Rochester Water Reclamation Plant	Rochester	11.33	23.85	MN0024619	Mar 2027	Clarifiers, Biogas silos, Biogas balloons	1
Met Council - Eagles Point WWTP	Cottage Grove	6	11.9	MN0029904	Oct 2023	Clarifiers	1
Grand Rapids WWTP	Grand Rapids	5.8	15.2	MN0022080	Jan 2025	Clarifiers, Uncovered lagoons	6
Moorhead Wastewater Treatment Facility	Moorhead	3.82	9	MN0049069	Jun 2026	Uncovered lagoons, Biogas silos, Biogas balloons	0
Owatonna WWTP	Owatonna	3.16	5	MN0051284	May 2026	Clarifiers, Biogas silos, Biogas balloons	9
Albert Lea Wastewater Treatment Facility	Albert Lea	3.06	12.5	MN0041092	Jan 2027	Clarifiers, Biogas silos, Biogas balloons	1
Alexandria Lake Area Sanitary District	Alexandria	2.95	4.7	MN0040738	Jul 2030	Clarifiers, Biogas balloons	0
Met Council - St Croix Valley WWTP	Oak Park Heights	2.54	5.8	MN0029998	May 2027	Clarifiers, Biogas silos	0
Marshall WWTP	Marshall	2.51	4.5	MN0022179	Feb 2029	Clarifiers, Uncovered lagoons, Biogas silos, Biogas balloons	16
Northfield WWTP	Northfield	2.15	5.2	MN0024368	May 2025	Clarifiers	0
Litchfield WWTP	Litchfield	2	3.1	MN0023973	Dec 2030	Clarifiers, Biogas silos, Biogas balloons	22
Saint Peter WWTP	Saint Peter	1.9	4	MN0022535	Mar 2027	Uncovered lagoons	15
Red Wing WWTP	Red Wing	1.66	—	MNL024571	Dec 2030	Clarifiers, Biogas silos, Biogas balloons	0
Elk River WWTP	Elk River	1.6	—	MNL020788	Dec 2030	Biogas silos, Biogas balloons	1
Met Council Hastings WWTP	Hastings	1.53	2.69	MN0029955	Mar 2030	Clarifiers	0
Long Prairie WWTP	Long Prairie	1.51	8.6	MN0066079	Apr 2023	Aerated lagoons, Covered lagoons, Uncovered lagoons, Biogas balloons	2
Fergus Falls WWTP	Fergus Falls	1.44	2.81	MN0050628	Aug 2028	Clarifiers, Biogas silos	2
Montevideo WWTP	Montevideo	1.35	3	MN0020133	Apr 2019	Biogas silos, Biogas balloons	27
Buffalo WWTP	Buffalo	1.23	—	MNL040649	Dec 2030	Uncovered lagoons, Carrousels / oxidation ditches, Biogas balloons	1
Cold Spring WWTP	Cold Spring	1.16	—	MNL023094	Dec 2030	Uncovered lagoons, Biogas silos, Biogas balloons	0
Rogers WWTP	Rogers	1.09	1.6	MN0029629	Mar 2026	Aerated lagoons, Uncovered lagoons, Carrousels / oxidation ditches, Biogas balloons	5

The 50 largest plants in Minnesota →Minnesota capital improvement plans →

Minnesota plants by treatment technology

Lagoon systems (341)Anaerobic digesters and biogas (106)Activated sludge and clarifiers (32)Oxidation ditches (30)

All 460 plants in Minnesota

Facility	City	Flow (MGD)
Met Council Metropolitan WWTP	Saint Paul	180
Blue Lake Wastewater Treatment Plant	Shakopee	26.54
Seneca Wastewater Treatment Plant	Eagan	20.92
Met Council - Empire WWTP	Farmington	12.05
Rochester Water Reclamation Plant	Rochester	11.33
Met Council - Eagles Point WWTP	Cottage Grove	6
Grand Rapids WWTP	Grand Rapids	5.8
Moorhead Wastewater Treatment Facility	Moorhead	3.82
Owatonna WWTP	Owatonna	3.16
Albert Lea Wastewater Treatment Facility	Albert Lea	3.06
Alexandria Lake Area Sanitary District	Alexandria	2.95
Met Council - St Croix Valley WWTP	Oak Park Heights	2.54
Marshall WWTP	Marshall	2.51
Northfield WWTP	Northfield	2.15
Litchfield WWTP	Litchfield	2
Saint Peter WWTP	Saint Peter	1.9
Red Wing WWTP	Red Wing	1.66
Elk River WWTP	Elk River	1.6
Met Council Hastings WWTP	Hastings	1.53
Long Prairie WWTP	Long Prairie	1.51
Fergus Falls WWTP	Fergus Falls	1.44
Montevideo WWTP	Montevideo	1.35
Buffalo WWTP	Buffalo	1.23
Cold Spring WWTP	Cold Spring	1.16
Rogers WWTP	Rogers	1.09
Bemidji WWTP	Bemidji	1.09
Monticello WWTP	Monticello	1.05
Chisago Lakes Joint Stc	Chisago City	1.03
Saint Michael WWTP	Saint Michael	0.96
Virginia WWTP	Virginia	0.94
Becker WWTP	Becker	0.91
Redwood Falls WWTP	Redwood Falls	0.89
Fortune Bay Resort & Casino	Tower	0.83
Luverne WWTP	Luverne	0.79
Two Harbors WWTP	Two Harbors	0.77
Big Lake WWTP	Big Lake	0.74
Smsc Water Reclamation Facili	Prior Lake	0.74
New Prague WWTP	New Prague	0.7
Annandale/maple Lake WWTF	Maple Lake	0.69
Crystal Lake Flocculation Treatment Facility	Robbinsdale	0.68
Cambridge WWTP	Cambridge	0.65
Kasson WWTP	Kasson	0.64
Chisholm WWTP	Chisholm	0.64
Plainview-Elgin Sanitary District WWTP	Plainview	0.62
Green Lake Sswd	Spicer	0.6
Stewartville WWTP	Stewartville	0.6
Madelia WWTP	Madelia	0.59
Granite Falls WWTP	Granite Falls	0.59
Whitewater River Regional WWTP	Saint Charles	0.58
Albertville WWTP	Albertville	0.58
Ely WWTP	Ely	0.56
Sauk Centre WWTP	Sauk Centre	0.56
Glencoe WWTP	Glencoe	0.55
Nkasd WWTP	International Falls	0.55
Delano WWTP	Delano	0.54
Pelican Rapids WWTP	Pelican Rapids	0.53
Saint James	Saint James	0.51
Otsego East WWTP	Rogers	0.51
Roseau WWTP	Roseau	0.5
Byron WWTP	Byron	0.5
Zumbrota WWTP	Zumbrota	0.49
Lake City WWTP	Lake City	0.49
Otsego WWTP West	Otsego	0.48
Spring Valley WWTP	Spring Valley	0.48
Grand Marais	Grand Marais	0.48
Cokato WWTP	Cokato	0.47
Princeton	Princeton	0.45
Belle Plaine WWTP	Belle Plaine	0.43
Saint Francis WWTP	Saint Francis	0.39
Montrose WWTP	Montrose	0.39
Le Center WWTP	Le Center	0.38
North Branch WWTP	North Branch	0.37
Zimmerman WWTP	Zimmerman	0.35
Preston WWTP	Preston	0.35
Eveleth WWTP	Eveleth	0.32
Hoyt Lakes WWTP	Hoyt Lakes	0.31
Watertown WWTP	Watertown	0.31
Mille Lacs WWTF	Onamia	0.3
Olivia WWTP	Olivia	0.3
Hinckley WWTP	Hinckley	0.29
Gilbert WWTP	Gilbert	0.29
Wadena WWTP	Wadena	0.29
Mountain Iron WWTP	Mountain Iron	0.28
Starbuck WWTP	Starbuck	0.27
Lonsdale WWTP	Lonsdale	0.26
Staples WWTP	Staples	0.26
Aurora WWTP	Aurora	0.26
Winsted	Winsted	0.26
Mora WWTP	Mora	0.26
Lake Crystal WWTP	Lake Crystal	0.25
Royalton WWTP	Motley	0.24
Coleraine-Bovey-Taconite Joint WWTP	Coleraine	0.24
Dawson WWTP	Dawson	0.23
Pine Island WWTP	Pine Island	0.23
Babbitt WWTP	Babbitt	0.23
Hector-Treatment Plant	Hector	0.22
Winnebago WWTP	Winnebago	0.22
Clara City WWTP	Clara City	0.22
Cannon Falls_wwtf	Cannon Falls	0.22
Kenyon WWTP	Kenyon	0.21
Sherburn WWTP	Sherburn	0.19
Blooming Prairie WWTP	Blooming Prairie	0.19
Clear Lake/clearwater WWTP	Clear Lake	0.18
Wabasha WWTP	Wabasha	0.18
Chatfield WWTP	Chatfield	0.18
Hawley-Treatment Plant #1	Hawley	0.17
Lakefield WWTP	Lakefield	0.17
Caledonia WWTP	Caledonia	0.16
Braham WWTP	Braham	0.16
Amboy WWTP	Amboy	0.15
Wanamingo	Wanamingo	0.15
Appleton WWTP	Appleton	0.15
Mayer WWTP	Mayer	0.14
Morristown WWTP	Morristown	0.13
Cologne WWTP	Cologne	0.13
East Gull Lake WWTP	East Gull Lake	0.13
Royalton WWTP	Royalton	0.11
Rushford WWTP	Rushford	0.11
Mahnomen WWTP	Mahnomen	0.1
Richmond WWTP	Richmond	0.09
Adams WWTP	Adams	0.09
Pine River Area Sanitary District	Pine River	0.09
Medford WWTP	Medford	0.09
Lester Prairie WWTP	Lester Prairie	0.08
Sacred Heart WWTP	Sacred Heart	0.08
Lewiston WWTP	Lewiston	0.07
Goodhue WWTP	Goodhue	0.07
Spring Grove WWTP	Spring Grove	0.06
Crosslake WWTP	Crosslake	0.06
Randall WWTP	Randall	0.06
Houston	Houston	0.06
Mabel WWTP	Mabel	0.06
Hokah-Well #1 Entry Point	Hokah	0.06
Vernon Center	Vernon Center	0.06
Maynard WWTP	Maynard	0.06
Saint Clair WWTP	Saint Clair	0.06
Oronoco WWTP	Oronoco	0.05
Avon WWTP	Avon	0.05
Harmony WWTP	Harmony	0.05
Darwin WWTP	Darwin	0.05
Waubun	Waubun	0.04
Ogilvie WWTP	Ogilvie	0.04
Halstad Municipal Utilities	Halstad	0.04
White Earth Wwsl	White Earth	0.04
Brownton WWTP	Brownton	0.04
Morton WWTP	Morton	0.04
Holland WWTP	Holland	0.03
Pennock WWTP	Pennock	0.03
Comfrey WWTP	Comfrey	0.03
Naytahwaush Wwsl	Naytahwaush	0.03
Orr WWTP	Orr	0.03
Brownsville WWTP	Brownsville	0.03
Lake Henry WWTP	Paynesville	0.03
Swanville WWTP	Swanville	0.02
Vermillion WWTP	Vermillion	0.02
Harris WWTP	Harris	0.02
Kerkhoven WWTP	Kerkhoven	0.02
Greenfield WWTP	Greenfield	0.02
Ogema WWTP	Ogema	0.02
Peterson WWTP	Peterson	0.02
Callaway WWTP	Callaway	0.02
Nett Lake Wwsl	Nett Lake	0.02
Nerstrand WWTP	Nerstrand	0.01
Minnesota City WWTP	Minnesota City	0.01
Isd 363 - Indus Public School	Birchdale	0.0094
Effie WWTP	Effie	0.0075
Palisade WWTP	Palisade	0.007
Ostrander	Ostrander	0.0069
Hammond WWTP	Zumbro Falls	0.0058
Bejou-Well #2 Entry Point	Bejou	0.0042
Lasalle	La Salle	0.004
Tamarack WWTP	Tamarack	0.0036
St George Community WW System	New Ulm	0.0028
Delft Sanitary District WWTP	Windom	0.0021
Laketown Community WWTP	Chaska	0.002
7-Clans Casino WWTP	Thief River Falls	—
Ada WWTP	Ada	—
Adrian WWTP	Adrian	—
Albany	Albany	—
Alberta WWTP	Alberta	—
Alden WWTP	Alden	—
Alvarado WWTP	Alvarado	—
Argyle WWTP	Argyle	—
Arlington WWTP	Arlington	—
Askov WWTP	Askov	—
Atwater	Atwater	—
Audubon	Audubon	—
Avoca & Iona WWTP	Iona	—
Badger Wastewater Treatment Plant	Badger	—
Bagley WWTP	Bagley	—
Balaton WWTP	Balaton	—
Barnesville WWTP	Barnesville	—
Barnum-Well #2 Entry Point	Barnum	—
Barrett WWTP	Barrett	—
Baudette WWTP	Baudette	—
Beaver Bay WWTP	Silver Bay	—
Beaver Creek WWTP	Beaver Creek Township	—
Belgrade WWTP	Belgrade	—
Bellechester WWTP	Bellchester	—
Bellingham WWTP	Bellingham	—

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Wastewater treatment in Minnesota: 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 September 11, 2026.

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