Norwich, CT

Norwich, CT

The City of Norwich is home to an estimated 39,470 residents, and it’s located in New London County, CT.

This report will help you become better acquainted with Norwich and the surrounding area by addressing the following questions:

  • Are there any hazardous sites in New London County, CT?
  • How clean is the air in New London County, CT?
  • What’s the average radon level for homes in New London County, CT?
  • Is the water in New London County, CT safe to drink?

Hazardous Sites near Norwich, CT

There is one Superfund site in New London County, CT. Superfund sites, like New London Submarine Base in New London, CT, are areas that have been contaminated with hazardous substances. If not for the cleanup efforts orchestrated by the EPA, these sites could endanger people living in nearby communities.

The EPA uses the Hazardous Ranking System (HRS) to quantify the risk a contaminated site poses to human health and the environment. Sites assigned HRS scores of 28.5 or greater qualify for placement on the National Priorities List (NPL), and are eligible to receive federal funding for cleanup efforts.

Before the EPA deletes a site from the NPL, it conducts reviews to ensure the cleanup was sufficient. As a result, some sites remain on the active site list long after cleanup activities are complete.

For more information about the Superfund site located in the Norwich, CT area, be sure to review the map and background information provided below:

Map Legend:


New London Submarine Base (HRS Score: 37)

The New London Submarine Base site is located in New London, CT.

Contaminants found at the New London Submarine Base site include:

  • Aluminum
  • Antimony
  • Arsenic
  • Barium
  • Benzene

Air Quality in the Norwich, CT Area

The two most widespread forms of air pollution are ozone (smog) and particle pollution (soot). Exposure to these harmful pollutants, for even just a short period, can have adverse effects on your health.

Thanks to data collected by air monitoring equipment located across the country, the American Lung Association (ALA) is able to assess and track our air quality using three metrics:

  • Ozone
  • Short-term Particle Pollution
  • Year-round Particle Pollution

In their 2019 annual report, the ALA rated the air quality in New London County, CT as follows:

Ozone Pollution

Grading Scale: A-F

Particle Pollution

Grading Scale: A-F

Particle Pollution

Grading Scale: Pass/Fail

Radon Levels in Norwich, CT Area

Air quality inside your home can be impacted by a number of factors, including the presence of hazardous substances in building materials (asbestos, lead, formaldehyde, etc.) and local radon levels.

Radon is a naturally occurring gas you cannot see or smell. It can build up inside your home and negatively impact your indoor air quality as well as your health.

To provide a guideline, the EPA assigned one of three zones to each U.S. county and county equivalent:

  • Zone 1 (higher radon levels)
  • Zone 2 (moderate levels)
  • Zone 3 (lower levels)

The average indoor radon reading in New London County, CT is predicted to be higher than 4 picocuries per liter (pCi/L), so the county has been assigned EPA Radon Zone 1.

EPA Radon Zone

The EPA Recommends acting to reduce your home's radon level if it's measured at 4 pCi/L or greater. So, if you're thinking about purchasing a home in Norwich, CT, you should strongly consider having a radon test performed.

Water Quality in Norwich, CT Area

In accordance with the Safe Drinking Water Act (SDWA), the EPA sets regulatory limits for drinking water contaminants known to cause adverse health effects.

The following New London County, CT water provider(s) violated the maximum allowable level for one or more regulated contaminants:

Filter ValueWater SystemContaminantHealth Effects
09011Ctwc - Country Mobile Div.Combined Radium (-226 and -228)Increased risk of cancer 
09011Ctwc - Country Mobile Div.Gross Alpha, Excl. Radon and UIncreased risk of cancer
09011Ctwc - Shoreline Region-masons IslandTotal Haloacetic Acids (HAA5)Increased risk of cancer 
09011Fox Laurel Mobile Home Park, LLCDi(2-Ethylhexyl) PhthalateReproductive difficulties; liver problems; increased risk of cancer 
09011Groton Long Point AssociationTTHMLiver, kidney, or central nervous system problems; increased risk of cancer 
09011Jewett City Water CompanyTotal Haloacetic Acids (HAA5)Increased risk of cancer 
09011Ledyard Wpca, Gales Ferry SystemTTHMLiver, kidney, or central nervous system problems; increased risk of cancer 
09011Montville Water SupplyTTHMLiver, kidney, or central nervous system problems; increased risk of cancer 
09011Norwich Public UtilitiesTotal Haloacetic Acids (HAA5)Increased risk of cancer 
09011Norwich Public UtilitiesTTHMLiver, kidney, or central nervous system problems; increased risk of cancer 
09011Rogers Mobile Home Park - GrotonNitrateInfants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. 

In addition to setting enforceable standards for harmful contaminants, the EPA also established guidelines to assist public water providers in managing the taste, odor and color of their drinking water.

To find out more about what’s in your drinking water, contact your utility company and request a copy of the latest Consumer Confidence Report.

Sources and Methods

Hazardous Sites: Identified using a report from the Environmental Protection Agency (EPA), hazardous sites detailed on represent sites contained on the National Priorities List (NPL) as of November 25, 2019.  The NPL is the list of national priorities among the known releases or threatened releases of hazardous substances, pollutants, or contaminants throughout the United States and its territories.  All site-related data was sourced from the EPA.

Air Quality: Grades for ozone, short-term particle pollution, and year-round particle pollution were obtained from State of the Air 2019, a report compiled by the American Lung Association.

Radon Zones: Radon zone designations were obtained using a public use dataset provided by the EPA (September 11, 2019).

Water Quality: Drinking water violation data was sourced from the Safe Drinking Water Information System (SDWIS), a public use database provided by the EPA.  The dataset included violations submitted to the database as of the third quarter of 2019.


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