Project Information

Executive summary

Over 800 communities across the United States, primarily in the Great Lakes and Northeast region, are burdened with a combined sewer system that collects and conveys both sewage and stormwater through the same pipes (U. S. Environmental Protection Agency, 2004 & Tibbets, 2005). Nineteen are in MA (shown in figure 1). During times of heavy rain, flow through these pipes can exceed the capacity of sewage treatment plants, resulting in the discharge of raw sewage into bodies of water to prevent sewage from backing up into streets and domestic spaces (EPA, 2017 & Massachusetts Department of Environmental Protection, 2019). While combined sewers present a clear danger to public health and safety, separating a combined sewer system can be expensive (Massachusetts Water Resources Authority, 2016). An alternative strategy to reduce discharges’ damage to public health is public notification of CSO events (United States Environmental Protection Agency, 2004). Community notification of combined sewer discharges is intended to reduce or eliminate the amount of people exposed to contaminated waters when recreating in them directly following a CSO event (U.S. EPA, 2004).

The Massachusetts legislature is considering a bill to standardize requirements for effective public notification of CSS discharges. “An Act Promoting Awareness of Sewage Pollution in Public Waters” (H.4921) would expand public notification requirements for any entity discharging effluent or industrial waste into public waters of the Commonwealth, including combined sewer permittees. The proposed requirements have 7 components: Initial public advisory of combined sewer discharge, initial notification of combined sewer discharge, permittee websites, an annual report from MassDEP, a MassDEP website, signage requirements for permittees, and permittee discharge monitoring requirements. The Act started gaining significant traction in 2017 after a heavily publicized combined sewer overflow resulting in over 8 million gallons of sewage dumped into the Merrimack river (Eddings, 2017). It was passed by the Massachusetts House in July 2020, and is currently being considered by the Massachusetts Senate Committee on Ways and Means.

The bill has bipartisan support in the legislature and the public, but as with every law, it is not without criticism. The bill’s heightened requirements present new challenges, as permittees are to send out notice faster, within 2 hours, and with more detailed information, discharge volume estimates. There are legitimate concerns with the costs, feasibility, and potential negative side effects of the bill. Permittees will be the most affected by the bill, as the majority of the proposed requirements are their responsibility to address.

The goal of our project was to provide recommendations to MassDEP regarding the effective implementation of proposed requirements in the “Act Promoting Awareness of Sewage Pollution in Public Waters”

Research Methods

We achieved our goal by:

  1. Characterizing how combined sewer overflows are currently monitored and reported in Massachusetts.
  2. Identifying the costs, challenges, and strategies for implementing the proposed requirements of H.4921.

To complete objective 1, we primarily used semi-structured key informant interviews and content analysis. We analyzed every regulatory document, including permits, consent decrees, and variances, for the 19 permittees in Massachusetts to determine their current community notification requirements. We also interviewed the four Chiefs of Wastewater Management and asked how they stored and used individual notices and the reporting practices for permittees in their region. To characterize how combined sewer discharges are monitored in Massachusetts, we conducted an informal conversation interview with a MassDEP statewide wastewater treatment operator about current metering and telemetry efforts in the Commonwealth. We also interviewed five of the nineteen permittees in Massachusetts and asked them about their metering and modeling efforts as well as how they send out initial notifications of discharges and who they send them to.

To complete objective 2, we used semi-structured key informant interviews with a purposeful sample of five Massachusetts Permittees and environmental officials from the Connecticut Department of Energy and Environmental Protection. Permittees were chosen based on their current practices and ability to represent a wide range of situations and resources, with at least one permittee in each region. We asked each permittee about their concerns with H.4921, the requirements they felt would be most difficult to implement, and the estimated costs associated with implementing the proposed regulations. We also interviewed officials in Connecticut because they implemented a law similar to H.4921, “An Act Concerning the Public’s Right to Know of A Sewage Spill” (Public Act No. 12-11), which went into effect in 2013. We asked them about the costs and challenges associated with implementing that law and for any advice or effective strategies that they had for MassDEP concerning the implementation H.4921.


Through our discussions with permittees, we learned a lot of information about current permittee practices and their concerns regarding H.4921. The public notification requirements for CSO permittees in Massachusetts are very decentralized. Each permittee is affected by a mix of unique permits, consent decrees, enforcement orders, variances, and even oral agreements. No
permittee is currently in compliance with all the proposed requirements of H.4921, but some are significantly more prepared than others. Because of this, we anticipate that the difficulty in implementing H.4921 will vary wildly between permittees.

Metering and modeling may be a challenge

  • Most permittees currently have some metering on outfalls, and a majority have metering on all outfalls.
  • Combined sewer systems can vary drastically in design, making some much more difficult and expensive to monitor.
  • Metering is costly to install and maintain.
  • Discharge monitoring has limitations.
  • There are limitations on the data collected from metering.

Initial notifications of wet weather discharges vary across the Commonwealth

  • The time frame for initial notifications varies, and none of the systems meet the proposed requirements of H.4921.
  • The information contained in initial notifications by permittees vary and do not yet meet the proposed requirements of H.4921
  • There is currently no statewide system to store discharge notifications
  • Permittees are concerned about their ability to verify discharges within the proposed time frame.
  • Permittees which do not send an initial notice for individual wet weather discharges will require a large increase in infrastructure and staffing.
  • Permittees expressed concerns about desensitizing the public to notices due to ubiquity or false positives.
  • Permittees expressed concerns about desensitizing the public to these notices, especially regarding discharge volume.
  • Some of the language in H.4921 is confusing or ambiguous to permittees.

All permittees have signage at discharge points

  • All permittees currently have signs at discharge points, but they do not contain the information outlined for signs in H.491 and are unlikely to be as effective as signs that do.

Website notifications vary per permittee

  • All permittees have established public websites, but most permittees do not post individual CSO notifications.
  • MassDEP posts limited information on CSOs on their website, but they have more information internally.

Few permittees have a subscriber based notification system for CSOs

  • Permittees with General Subscription Services for Other Notifications may be able to use them for CSO notifications.
  • Subscriber-based systems are an additional cost for permittees, but demand for such systems is limited.


We proposed nine recommendations to the MassDEP to help implement the requirements
in H.4921.


  1. We recommend that MassDEP work with Massachusetts legislators to reduce the unintended effects of the legislation. While all interviewees praised the bill’s intent and acknowledged that they could be doing a better job to inform the public of combined sewer discharges, they also commented that the legislation had potential to cause unintended negative consequences for permittees and the public. Many of the concerns we heard from permittees, such as the potential for the inclusion of volume to mislead the public, could be addressed by changing the bill’s public notice requirements. We recommend that MassDEP work with legislators to re-evaluate these requirements and determine if they are truly necessary to protect public health.
  2. We recommend that MassDEP work with Massachusetts legislators to clarify the language of H.4921. This would clear up any confusion permittees may have about H.4921’s requirements and enable better discussion about what resources permittees will need, allowing them to move forward in preparing for the law.
  3. We recommend that MassDEP develop a process to make funding available to permittees for the purposes of implementing the requirements in H.4921. Many permittees that we interviewed told us that they would require a significant increase in funding, typically about $25,000 per year per outfall or $500,000 total. We recommend that MassDEP develop a process to make funding available for permittees so that they can comply with these requirements if and when the bill is passed.
  4. We recommend that MassDEP establish a standard process for permittees to send discharge notifications. A standardized reporting system would make it easier for MassDEP to store CSO reports, analyze data, and post these notifications to their website because it would also require all permittees to report the same format of data regarding discharges in their areas. This would be done best using a CROMERR compliant online portal so that permittees do not have to send their notice to the EPA separately.
  5. We recommend that MassDEP collaborate with MWRA to create metering guidelines for Massachusetts permittees. Many permittees commented that it is difficult to determine where meters can be effectively placed. A representative from the MWRA told us that they have spent months determining where their meters need to be placed to get the right information out of them. While every permittee faces a different situation regarding their regulators, broad guidelines for metering based on what the MWRA learned through their efforts could help permittees reduce the cost of their metering.
  6. We recommend that MassDEP publish a GIS showing where combined sewer outfalls are in the Commonwealth and historical data pertaining to them. The intent of the law is to promote transparency and public understanding of sewage pollution. We recommend that MassDEP publish their internal GIS system to convey historical information. This GIS should be updated occasionally, and should not be a live representation of active discharges. Environmental health
    officials in Connecticut ardently cautioned against live updating a GIS for individual discharge notifications.
  7. We recommend that permittees self-assess their ability to meet the requirements of H.4921. Each permittee has a different level of preparedness to implement H.4921. The assessment can help MassDEP identify permittees which are less prepared to implement H.4921 and focus their resources on permittees with the greatest needs.
  8. We recommend that MassDEP collaborate with health officials in communicating proper precautionary measures when CSOs occur. Prior research shows that communication of a potential hazard and explicit warnings of the mechanism of injury have been associated with greater hazard understanding and intent to act cautiously. To increase compliance with suggested precautions and improve public awareness of combined sewers, MassDEP should collaborate with state and local health departments to develop standard language for use in all signage and  discharge notifications across the Commonwealth to describe discharges, the threats they pose to public health, and precautionary measures. Since the signs specified by H.4921 will be more effective warning signs than the existing signs, these signs should be “phased out” by replacing stolen, vandalized, or damaged signs with the ones specified by H.4921.
  9. We recommend that MassDEP conduct further research into H.4921’s impact on other types of discharges. The Bill H.4921 is applicable to all permittee discharges including SSOs, dry weather combined sewer discharges, and wet weather CSO discharges. Since we primarily researched this bill’s impact on CSO permittees, MassDEP should conduct further research into the implications the new regulations may have on the notification practices of other overflow events.


Our results show that while a few permittees are ready for this legislation, the majority are going to require increases in funding to meet the new requirements. Most of our recommendations focus on MassDEP working with legislators to revise and clarify some of the language in the bill as well as provide some sort of assistance to permittees in the transition to the standards of this new bill. A deeper look into the environment surrounding CSO events reveals that while a mutual desire for public notification exists, there are many legitimate concerns with the specific proposed regulations. Until combined sewers can be replaced, public
awareness of discharges is the public’s last line of defense for the numerous health risks they introduce and are an important component of our transition to a more environmentally conscious world.