Sanitary Sewer Overflows (SSOs)

What is an SSO?

A Sanitary Sewer Overflows (SSO) is an unintentional discharge, spill, or release of untreated wastewater to the environment or a property prior to reaching a treatment facility.

Causes of SSOs or Sewer Backups

SSOs occur infrequently, when the capacity of the sewer system is exceeded—usually due to extreme conditions such as heavy rainfall or an obstruction or break in sewer lines. During such events, flow may be discharged to local receiving waters, without treatment, as a last resort to reduce the risk of sewage backing up into homes and businesses.

Effects of SSOs

Public health officials recommend avoiding contact with SSO discharges in receiving waters for up to 48 hours after the discharge has ended, as there may be increased risks due to exposure to potential disease-causing organisms and pollutants. Untreated sewage overflows into basements and can cause property damage and threaten public health. 

To receive SSO Notifications please sign up using the Town's CodeRED/Alert Brookline system (link below):

如需接收 SSO 的相关通知,请使用本镇的 CodeRED 系统进行注册:


In addition to CodeRED, the Town will issue public advisory notifications via social media (Facebook, Twitter), two local news organizations, and the Town's Meeting member list.

SSOs in Brookline:

There are currently no reported SSOs. In the event of an SSO, a public advisory notification will be issued by the Town. On business days, this website will be updated within six hours of the notification. During weekends or holidays, this website will be updated on the next business day. Information and updates will be remain posted for 30 days following the cessation of the SSO.

You can also follow this link for a list of discharge and overflow events on the MassDEP website. This list is updated within 24 hours of when the public advisory notification is sent. Enter 'Brookline' in the Permittee field and click “Search”.

Prevention of SSOs:

SSOs have several causes, including sewer blockages, line breaks, or when the sewer system is overloaded. SSOs can be caused by improper disposal of grease or rags that can block sewer lines. Never pour grease down sink drains or into toilets, and never put solids into grease traps or interceptors.

Despite their name, “flushable” wipes do not degrade in the sewer system and can cause clogs in sewer lines. These should be disposed of in the trash, not flushed down the toilet. These include bathroom wipes, baby wipes, and disinfecting wipes. Homeowners can also take action to reduce unnecessary stormwater entering the sewer system—including ensuring that their downspouts and sump pumps do not discharge to sewer drains.

Brookline's Response to an SSO:

Brookline is required to report all overflows to the Massachusetts Department of Environmental Protection, the Environmental Protection Agency, and the Town's Public Health Department. The Water & Sewer Department coordinates SSO discovery and response.

Related information on cleanup, repair, and SSOs refer to the following links: