CSO Activations

DATE OF ACTIVATION CHE003 DISCHARGE AMOUNT [MG]

CHEOO4 DISCHARGE AMOUNT [MG]

CHE008 DISCHARGE AMOUNT[MG]

  Boston Inner Harbor off end of Winnisimmet Street Chelsea River off end of Pearl Street under the Andrew McArdle Bridge Chelsea River off Eastern Avenue in line with old Willoughby Street
05/15/2020 0 0 0.04132
05/30/2020 0 0 0.015316
06/11/2020 0 0 0.011735
06/28/2020 0 0.117983 0.253361
06/29/2020 0 0.313702 0
07/17/2020 0 0.6466 0
07/23/2020 0 0.066371 0.184681
08/04/2020 0 0.025517 0.020993
09/30/2020 0 0 0.014896
10/13/2020 0 0 0.02219

11/23/2020

0

0.017932

0.042608

12/1/2020 0 0 0.015957
Totals for 2020 0

1.188105

0.623057
03/28/2021 0 0 0.027877
06/22/2021 0 0.106587 0.701971
07/01/2021 0 0 0.822101
07/02/2021 0 0.702123 0
07/09/2021 0 0 1.352611
07/12/2021 0 0 0.003658
07/12/2021 0 0 0.172040
07/27/2021 0 0 0.227265
07/30/2021 0 0 0.048165
08/9/2021 0 0 0.069383
08/19/2021 0 0.050299 0.271517
08/22/2021 0 0.014682

0.015025

09/01/2021 0 0 1.482459
09/02/2021 0 0.051107 0
09/09/2021 0 0 0.127535
09/16/2021 0 0 0.033838
09/28/2021 0 0 0.054198
Totals for 2021 0 0.222675 4.057032
10/13/2022 0 0 0.021
10/14/2022 0 0 0.078
11/30/2022 0 0 0.088231
Totals for 2022 0 0 0.187231
3/14/23
0 0 0.001818
7/10/23 0 0 0.0032
7/16/23  0 0.002763 0.0084
7/21/23 Unknown 0.056221 0.228583
7/29/23 0 0 0.598297
8/8/23 0 0 0.116148
01/10/24 0 0.010955  0.086920
6/14/24 0 0.012873 0.153999
07/05/24 0 0.002776 0.012354


Last CSO Activation

Updated on July 5, 2024

In accordance with NPDES Discharge Permit MA0101877, the City of Chelsea is providing this notice of the following Combined Sewer Overflow (CSO) activation(s):

CHE003: Mystic/Chelsea River confluence off end of Winnisimmet Street
Date of Activation: did not activate

CHE004: Chelsea River off end of Pearl Street under the Andrew McArdle Bridge
Date and time of discharge: 7/5/24 7:50AM
Date and time discharge ended: 7/5/24 8:00AM
Duration: 10 minutes
Average overflow volume for the past 3 years: .19MG

CHE008: Chelsea River off Eastern Avenue in line with old Willoughby Street
Date and time of discharge: 7/5/24 7:55AM
Date and time discharge ended: 7/5/24 8:05AM
Duration: 10 minutes
Average overflow volume for the past 3 years: .21MG

Please note that this notification is based on preliminary metering data, which has been identified as being impacted by tidal conditions. Please do not use the data contained in this notice for official purposes. Final activation data may be obtained from official discharge monitoring reports submitted to the Environmental Protection Agency on a monthly basis, or from the City’s CSO Annual Report, which is posted on the City’s website.

Additional information regarding Chelsea’s CSOs is available on the City’s website. For specific information about this CSO activation, please contact:

Cate Fox-Lent
Department of Public Works
500 Broadway, Room 310
Chelsea, MA 02150
617-466-4203
cfox@chelseama.gov