Sewage/Wastewater Treatment

Posted Dec 15, 2019
Sewage Bypasses and Combined Sewer Overflows Dec 13-15, 2019

Below is a map made from CT Department of Energy and Environmental Protection (DEEP) data that shows sewage spills reported to CT DEEP during the storms of 13-15, 2019. If no town names and location symbols appear at first, try refreshing the page. You can zoom in by double-clicking between symbols. If you click on a symbol and the pop-up box is too small to read, try the “enlarge” button in the upper right of the box.

If you click the link above the map, it should open a new, larger page that can be zoomed, adjusted for better viewing, and clicked on for more information.

Sewage Spills Electronically Reported Dec 13-15, 2019

Heavy rainfall that gets into sewage treatment systems through damaged pipes, leaky manhole covers, illegal connections from storm drains, and other ways, often causes sewage to overflow at treatment plants or from manholes, or to back up into the basements of homes and businesses. Most sewage treatment systems now report these “bypasses” to the CT DEEP, and then they are mapped out on DEEP’s Sewage Right To Know website.

Posted Jul 25, 2019
Some comments about mapping state data

A request for information about state GIS files led to some comments that our members may find useful.

The CT Department of Energy and Environmental Protection (DEEP), has been a leading provider of high quality GIS data for years. Over the past few years DEEP, other state agencies, UCONN’s CLEAR project, local municipalities, and many private organizations have been using online map displaying services from ESRI, Google, and other sources to display maps on their webpages. Services from these companies are available for anyone to use with little GIS experience, usually for free, and the maps and the data files used to make them are usually published publicly for anyone to use.

Although the comments below were in response to a question regarding DEEP’s Sewage Right To Know system, they may have value to any organization looking for ways to create and display maps using public data. The first time you use one of these maps may be daunting because of the many options for turning layers on and off mutiple sets of tabs to open or close, and because what is displayed may change as you zoom in. Usually a large screen is required to use the maps well, so trying them by phone is not recommended.

The DEEP people are the authority on all things related to sewage events, but I can share and show you what I do as a Rivers Alliance of CT staff person and amateur GIS enthusiast. I made a quick map to see what was possible, it is at:

The data file I use is described at this link. Any GIS analyst can probably take it from there without any of my ideas, but I can at least provide some observations.

I use ESRI’s ArcGIS Online free membership services, so what I have done is limited to what is publicly available from other sources. I have uploaded very little original material, all citations must reference the original sources, not me. The website you referenced is part of DEEP’s exhaustive work to provide public access to information under the Sewage Right To Know act. Their Right To Know webpage is related mostly to Combined Sewer Overflows, but the same reporting system is used for Bypass events. Their Sewage Reporting webpage is for the local authorities who have to report to them.

The location information DEEP has on file from before the online system went into effect, you will have to get from them directly. Also, pollution by everything else that does not meet the specific definitions of a Bypass event, is not reported as such online. For example, even if a pollutant comes out of a pipe from a treatment plant that was not supposed to, if it was not technically a Bypass, it will not be in the data. It has to be reported and DEEP will act on it fast, of course, but it cannot be included with data identified as a Bypass.

The locations given for Bypass events are (I believe) where the sewer pipes were, not where the sewage got into a waterway. They identify in their reports if sewage reached a waterway, and the name if known , but not in most cases a specific municipal storm sewer outfall.

Clicking on a symbol for a Bypass event provides a pop-up box with more of the information provided by the local authorities. Some reporting officials provide better information than others of course, and it’s probably easy for them to overlook a data field or two. For example, I have seen reports of sewage getting into a storm drain, but the field for reaching a waterway is marked “No” even though most storm drains lead to water somewhere. I has seen reports checked “No” about reaching a waterway, but the name of a stream is given, sometimes even with a careful description of how the sewage got there. The DEEP people are really good at answering any questions you may have about specific instances.

There can also be errors in latitude and longitude. A quick look at the map of all reports shows a lot of spills in Southington, but many of them were reports from Waterbury WCF. I have to assume a slight mistake in longitude. That’s why there is a section on most maps to turn layers on and off so you can look for discrepancies. Also, the names and emails of the people who did the reports are in the data tables that are usually available, though may not be in the pop-up.

Tony Mitchell, Map Guy for Rivers Alliance of CT

Posted Dec 13, 2018
Rivers Alliance comments to MDC on their proposal to delay CSO elimination

For: Scott W. Jellison, Chief Executive Officer, The Metropolitan District Commission, Hartford, Connecticut

From: Rivers Alliance of Connecticut

Thank you for the opportunity to comment on the MDC Long Term Control Plan (LTCP) Draft Update for control of its combined sewer overflows (CSOs). The mission of Rivers Alliance is to protect the health of all state waters. For 25 years, we have advocated directly or through our Board for cessation of the sewage spills from the MDC system. We appreciate that you have made  progress, and urge you to pick up the pace.

The 2006 Consent Decree from the EPA and the CT DEP was long overdue. The schedule for remedial action was reasonable, and the state has responded positively to the MDC’s requests for help with the costs of the project. Nevertheless, the MDC is now proposing a dramatic slowdown in meeting the terms of the Consent Decree and the diversion of resources to other projects. It appears that the MDC wants to change the deadline for completion from 2029 to 2058. That’s another whole generation of people who will be exposed to raw sewage.

The MDC should proceed on the schedule for CSO work that it has agreed to. We oppose further delay.We support the points made by our expert colleagues at Connecticut Fund for the Environment/Save the Sound and at the Connecticut River Conservancy, and will not repeat them here. I am sure that we all agree to the overarching principle that it a basic social responsibility of individuals and communities not to subject their neighbors to raw sewage. Sewage treatment is expensive, for households as well as municipalities. But it is not an obligation one can put off without serious consequences. Exposure to raw sewage is disgusting and dangerous. It is obviously harmful to human health. It is even more harmful (though less obviously) to aquatic life.

I’ve read comments sent you by the Jorgensen family on the North Branch of the Park River. Connecticut residents should not have put up with the constant close encounters with river sewage that they describe. Many MDC customers and visitors to the region praise the excellent quality of your drinking water. The same high professional standards should be applied in the wastewater side of your business. Those standards include, in our view, staying on schedule.

Thank you for your consideration.

Margaret Miner, Executive Director, Rivers Alliance of Connecticut

Posted Dec 12, 2018
MDC Proposes Delayed Elimination of Combined Sewer Overflows

The Metropolitan District Commission (MDC) held a public hearing Dec 11 on it’s proposal to modify it’s 2014 agreement to eliminate combined sewer overflows (CSOs) by 2034 using a massive tunnel system under Hartford. MDC wants instead to separate the sanitary sewers from the stormwater drains in the north end of the city and put off building part of the tunnel system until well beyond 2034. It calls its plan their Clean Water Project.

In a 2017 letter to MDC, the CT Department of Energy and Environmental Protection (DEEP) reiterated the need to eliminate CSOs. Here’s an excerpt:

“For the past eleven years, DEEP has worked with MDC in order to meet the changing needs of the Clean Water Project. DEEP modified Consent Order WC5434 and supported revisions to the LTCP that resulted in more cost-effective ways to meet the environmental goals. DEEP agreed to schedule modifications in the CO to extend compliance deadlines by eight years. DEEP agreed to merge the solution to salutary sewer overflows and CSOs into the South Hartford Conveyance and Storage Tunnel (SHCST) and provided a very favorable is grant award for the project. To date, DEEP has provided $1.2B in financing to support MDC’s two funding authorizations of $1.6B, or 75% of project funding with CWF participation.”

“DEEP intends to continue to work with MDC in implementing the approved LTCP and LTCP Updates as we move forward. We recognize future updates may include additional alternatives analyses evaluating means of keeping this project as cost-effective as possible. However, the standards of elimination of CSO’s tributary to the North Branch Park River and Wethersfield Cove and control of CSO to the one-year level, established in Consent Order WC5434, shall not change.”

The deadline to submit public comments is December 13, 2018 at 6:00pm and may be submitted to the District Clerk via email at or via mail at: The Metropolitan District 555 Main Street Hartford, CT 06103 Attn: District Clerk

Links to more information:

Posted Oct 09, 2018
The big Naugatuck River sewage spill was one year ago

Waterbury’s Sunday Republican-American newspaper on Oct 7 had an excellent look at the Naugatuck River one year after a power failure caused 5 million gallons of untreated sewage to enter the river. Michael Puffer reviewed news stories from a year ago and went on to report on the work of Naugatuck River Revival Group founder Kevin Zak to monitor the cleanup of the river and in organizing additional work to make the Naugatuck better than it was before the spill. Click here to go to the newspaper’s archived introduction to the story, full access requires a subscription however.

The sewage spill Right To Know law was modified last legislative session, and improvements to the system continue to be implemented. Click here to go to the DEEP webpage that opens to a map of reported sewage spills that do not have a date the spill ended entered into the online system. You have to click on various tabs to make your own map showing archived spills to see all of them, then you can sort a table to find recent ones.

As an example of the information now available, here is our map of all reported sewage spills in towns along the Naugatuck River since those towns began using the electronic system. Note some reports have incorrect reported latitude or longitude that makes the symbol appear in the wrong location on the map. We are assured these errors will be fixed eventually.

Because spills are often in the same location, you have to zoom into a particular town, then click on a symbol to get details. For example, clicking on a symbol near Waterbury’s treatment plant pops up a box that says “1 of 5”, then you can click on the arrow to see the next description.

Sewage Spills Reported by Naugatuck River Towns: A Draft Map by Rivers Alliance

Posted Oct 05, 2018
A look at the sewage spills of Oct 1-3, 2018

Below is a map made from CT Department of Energy and Environmental Protection (DEEP) data that shows sewage spills reported to CT DEEP during the storms of Oct 1-3, 2018. If no town names and location symbols appear at first, try refreshing the page. You can zoom in by double-clicking between symbols. If you click on a symbol and the pop-up box is too small to read, try the “enlarge” button in the upper right of the box.

View map of reported sewage spills Oct 1-3, 2018.

Heavy rainfall that gets into sewage treatment systems through damaged pipes, leaky manhole covers, illegal connections from storm drains, and other ways, often causes sewage to overflow at treatment plants or from manholes, or to back up into the basements of homes and businesses. Most sewage treatment systems now report these “bypasses” to the CT DEEP, and then they are mapped out on DEEP’s Sewage Right To Know website.

The DEEP sewage mapping system is still under development. If you are concerned about unreported sewage spills into a particular river, call your local treatment plant.

Also, there are places in Connecticut where the storm drains and the sewage pipes are combined into one system. With high rainfall, many of these combined pipes are designed to overflow into rivers and streams so the wastewater treatment plants are not overwhelmed. The DEEP has a map of Combined Sewer Overflows that shows the six urban areas where these can occur. Zoom in to any of them to see exactly where the combined flow may enter streams and rivers. Not every rain event is enough to cause these overflows, but it’s a good idea to avoid contact with the water downstream of them after significant rain until you can confirm if there were any sewage spills.

Posted Sep 09, 2018
MDC and DEEP in Ongoing Discussions Re Landfill

The Metropolitan District Commission (the Hartford–based regional water utility) has backed off its threat to cease working with the Department of Energy and Environmental Protection for the disposal of wastewater from the Hartford Landfill. For now, the two parties are discussing the issue. Here’s the Courant article on the outbreak of peace negotiations.

Posted Jul 31, 2018
MDC Threatens to End Landfill Discharge Sept. 1 if CT DEEP Doesn’t Pay Disputed Sewer Fees

Is CT DEEP discharging pollutants from the now-closed Hartford Landfill into the sewer system operated by the Metropolitan District Commission? The MDC says yes, a position DEEP vigorously opposes. A three-year dispute over this issue has recently culminated in MDC’s issuing an ultimatum to DEEP: As of Sept. 1, MDC will terminate the discharge into its system unless DEEP either finds an alternative to using MDC’s system or pays the outstanding sewer fees of nearly $6 million that MDC claims DEEP owes.

Before mid-2016, MDC had charged DEEP the normal rate for “ordinary domestic sanitary sewage.” But the commission claims that testing of the discharge revealed the presence of ammonia-nitrogen, and subsequently began charging the much higher rate for discharges requiring remediation. As a result, DEEP’s bill for the discharges rose from roughly $10,000 a month to nearly $270,000 month – a 27-fold increase, which DEEP Commissioner Robert Klee called “unconscionable.”

DEEP insists that the discharge is “environmentally appropriate,” according to a July 9, 2018, letter Commissioner Klee sent to MDC Chairman William DiBella. Commissioner Klee also said the nature of the discharge has not changed since MDC assumed responsibility from the former Connecticut Resources Recovery Authority for the Hartford Landfill discharge into its water pollution control facility. Consequently, DEEP refuses to pay the increased fee.

Several years ago, the state legislature turned legal obligations and control over the Hartford Landfill to DEEP.

More news:

Posted Jul 13, 2018
Sewage Spills in CT Reported Electronically in the Last Three Days

This is an experimental map based on information available publicly from a file automatically updated by the GIS people at the CT Department of Energy and Environmental Protection. Please keep in mind that not all facilities and treatment systems report electronically, and this data has not been verified by either DEEP or Rivers Alliance. Also shown are public water supply watersheds in blue and aquifer protection zones in red. Click the >>>> symbol to see the legend and some controls for turning features on or off.

View the map

Posted Jan 22, 2018
Naugy Suffers Again


The Naugatuck River can’t seem to catch a break. As if it wasn’t bad enough to get vaguely associated with Legionnaires Disease in December, and after a five million gallon sewage spill October 9, on Saturday, January 20, 4000 to 6000 gallons of hydraulic fluid spilled from a Somers Thin Strip in Waterbury, contaminating the factory grounds, pavement, soil and storm-water catch basins. Much of it reached the River. The Waterbury Fire Department put oil booms in the river, but most of the oil had already flowed downstream. CT DEEP took over cleanup of the river.

Other Naugatuck River Problems

According to DEEP’s Bypass and CSO Events Public Viewer there were 6 other sewage spills into the Naugatuck River in 2017 in addition to the big one described above. 2 of them occurred since the famous Oct 9 spill. During the massive rain storms Oct 29-30, from 100,001 to 500,000 gallons of sewage got into the river from an overflowing manhole at Waterbury’s treatment plant, and from 501 to 1000 gallons overflowed from a manhole on High Street in Naugatuck.

Earlier in 2017 from 1,001 to 5,000 gallons of raw sewage reached the river from a spill on Derby Avenue in Seymour September 9. The Waterbury treatment plant had a spill estimated to be anywhere from 500,001 to 1,000,000 gallons on April 16. A spill on Church Street in Naugatuck on February 7 spilled an unknown amount of sewage in the river. The Naugatuck’s bad year began on Jan 20, 2017 when 650 gallons of raw sewage was bypassed into the Naugatuck River from the City of Naugatuck’s treatment plant.

However, if there were any sewage spills in Beacon Falls in 2017, they would not show up on the list above because that system does not report electronically to DEEP. The other sewage treatment plants on the Naugatuck, in the cities of Derby, Naugatuck, Seymour, Shelton, Torrington, Thomaston, and Waterbury all report electronically.

Posted Jan 16, 2018
Are Sanitary Sewer Lines Leakproof?

(Note that after this article was written, the Litchfield Water Pollution Control Facility reported a raw sewage bypass during the major rain event 1/23/2018 from a manhole near Tapping Reeves condominiums at 354 Bantam Rd, Litchfield. They estimated from 1,001 to 5,000 gallons of raw sewage entered Moulthtop Brook because of “Line Blockage – Grease.” Moulthrop Brook leads to Little Pond and the Bantam River upstream from Bantam Lake. They note that a resident noticed an odor on Monday, Jan. 22, 2018 and they contacted the sewer department on Tuesday, Jan. 23. The estimated amount of sewage that leaked was based on visual observations at the time of the repair and the length of time that had passed since the odor was first noticed. Also that day leaks of 501 to 1,000 gallons were reported by Norwalk, and 51 to& 500 gallons were reported by Meriden.)

According to news reports, 2 or 3 million gallons of sewage closed several Nantucket, MA, streets January 4-8 and reached their harbor from a catastrophic failure of a force main. Force mains are pressurized pipes through which sewage is pumped. At a January 10th community meeting, the town provided updates on the extraordinary effort it took to stop the leak and begin repairs.

Force main sewer lines are a topic of attention here in CT partly because a new force main is being proposed by the Woodridge Lake Sewer District to fix problems with their treatment plant in Goshen by pumping their sewage to an existing sanitary sewer line on the west side of Torrington. Part of that force main would pass through a portion of the watershed of one of Torrington Water Company’s reservoirs. Woodridge Lake Sewer District insists that leaks (such as Nantucket’s) are very unlikely. The City of Torrington has scheduled a Jan. 31 presentation and a Feb. 20 hearing on the Woodridge Lake Sewer Discharge Permit.

What information is available about the frequency of sanitary sewer failure in Connecticut?

According to DEEP’s Bypass and CSO Events Public Viewer, since September 2016 from 116,993 to 641,250 gallons of sewage spilled into our waterways from places in public wastewater systems other than at the treatment plants and were not connected with rain or snowmelt. Here’s the breakdown:

  • 5,262 to 12,600 gallons spilled from 13 incidents reported on Sewer Mains caused by Mechanical Equipment Failure (1 incident) Sewer Line Blockage – Other (4 incidents) or Unknown (8 incidences).
  • 111,731 to 628,650 gallons spilled from 32 spills from manholes caused by Mechanical Equipment Failure (2 spills), Sewer Line Blockage – Grease (14 spills), Sewer Line Blockage – Other (11 spills), Sewer Line Blockage – Roots (3 spills), Unknown (2 spills).

There are many other reports in the Bypass and CSO Events Public Viewer that do not give any amounts but only report where the spills occurred and what water bodies were affected. The information on the Bypass and CSO Events Public Viewer is from the 82 utilities that report electronically to DEEP. This count does not include any sewage incidents from the 33 sewage treatment plant systems that do not report electronically.

A quick Google search for force main failures in Connecticut uncovered few instances specific to our state. In 2007 Wallingford had to repair an offshore cast-iron force main. A report on West Haven’s system refers to two force main breaks in the last 15 years. Regional Water Authority’s PipeSafe insurance plan for sanitary sewer service specifically excludes force mains.