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Charles River

EPA Region 1 – Petition Review & Stakeholder Engagement Process FAQs

Charles River (Massachusetts) Residual Designation Petition

September 28, 2020

As the EPA Region 1 office considers how to respond to the pending petition for residual designation ("RD") in the Charles River watershed, it will be engaging with stakeholders throughout the watershed. Region 1 held a series of stakeholder engagement introductory webinars on September 16 – 18, 2020. Materials on the RD petition, EPA contact information, and materials from the webinars are online at:

During the September 2020 engagement webinars, EPA was asked about the state of the Charles River, the mechanics of EPA's proposed RD review process, and about what permitting might look like if the agency determines the petition should be granted (in full or in part). As the agency stated during the webinars, no decision has been made regarding the merits of the permit. Some of the questions most frequently asked of the agency, and a summary of EPA's responses, are included below.

Note that these webinars were not official hearings; the notes below were not taken from any stenographic record, they were only summarized from EPA staffs' impressions of the post-presentation conversations.

Stakeholder Engagement Process Questions

  1. What exactly is the petition asking the EPA to consider?

    The May 9, 2019 petition from the Conservation Law Foundation and Charles River Watershed Association asked EPA to exercise its residual designation (RD) authority to regulate certain stormwater discharges from privately owned commercial, institutional, industrial, and multi-family residential properties that are one acre or greater in the Charles River watershed.

  2. What's EPA's plan for reaching out to property owners and other stakeholders?

    EPA is working with the Consensus Building Institute (CBI), an independent, non-partisan facilitator with no stake in the outcome. CBI, in close coordination with EPA's team, will engage with stakeholders directly in the coming months to better understand what key questions need to be answered, as EPA moves forward with the review of the petition. For more, please contact Pat Field (, Senior Mediator at CBI .

    Additionally, EPA welcomes all assistance with spreading the word about this process; please feel free to connect us to other interested stakeholders by phone, through Pat Field at CBI, or via email at

  3. Who received EPA's August 2020 stakeholder engagement letter and who did EPA invite to its introductory webinars?

    EPA sent word about the stakeholder engagement process and the planned introductory webinars to a broad email list of municipal, industrial, commercial, and public sector stakeholders. EPA also worked with several association and coalition partners to further spread the word. The three webinars were co-hosted by some of these partners, including the Massachusetts Municipal Association, NAIOP, and the Massachusetts Rivers Alliance.

  4. Can you share the petition and the data used by the petitioners?

    Materials relating to this stakeholder process, including the petition, are available online at Please reach out to EPA at or via the "Contact Us" form on the website above if you need assistance accessing those materials.

    Additionally, as EPA reviews this petition, the agency welcomes any additional quality assured stormwater quality data (including studies that document rooftop and ground-level source areas) that stakeholders feel would be helpful for EPA to consider.

  5. Can the petition be changed based on stakeholder input?

    EPA cannot change the petition it received; the agency's role is to carefully consider the petition and decide how best to respond. The petitioners, Conservation Law Foundation and the Charles River Watershed Association, can always amend petitions submitted to the EPA – with or without cause.

  6. I'm aware of some site owners and institution partners that did not receive the letter and weren't able to join the webinars; is there any way to help make sure they're in the loop?

    Please feel free to connect us to other interested stakeholders by phone, through Pat Field (, Senior Mediator at CBI , or via email at

  7. We'll have more questions for EPA once we work internally to review this issue, how can we best contact EPA about this?

    EPA, with CBI, will be working to set up one-on-one and small group stakeholder calls to discuss this review in further detail, to answer any more questions you may have, and to solicit feedback on questions EPA may have for certain stakeholders. The agency welcomes your questions anytime (feel free to call us, or email us at Also, if you would like to inquire about a small group session with EPA, please contact us at the email address above, or reach out to Pat Field (, Senior Mediator at CBI .

  8. How will EPA be working with Massachusetts DEP on this petition review?

    EPA and MassDEP have been communicating about this RD petition since it was received in 2019. MassDEP was also able to join all three of the EPA's introductory stakeholder webinars. EPA will continue to discuss its review with MassDEP throughout this stakeholder process and, if the petition is granted (or granted in part), will consult with MassDEP on any next steps such as development of potential stormwater permits.

  9. What are EPA's next steps, and what's the timeline for this process again?

    EPA plans to conduct additional outreach, including small group stakeholder meetings, with interested members of all sectors (e.g., commercial, industrial, residential, municipal, public sector) over the next couple of months. EPA anticipates concluding this engagement in November 2020 at which point the agency will internally review its record to determine how to respond to the petition.

Specific Residual Designation Petition & Charles River Questions

  1. Will EPA be looking to make town-by-town decisions here or a uniform watershed-wide approach?

    EPA has not made any decisions yet regarding the substance of the petition – including whether to have town-by-town or watershed wide requirements (or even a mixture of both).

  2. Will EPA be developing general or individual permits using this RD authority, and what kind of stormwater controls might EPA require of future permittees?

    EPA has not made any decisions yet regarding the substance of the petition – including whether individual or general permits would be required for any discharges in the Charles River watershed, or what stormwater control measures may or may not be considered for such permits.

    For information on what stormwater control measures the towns within the watershed may be considering as they work to implement their Municipal Separate Storm Sewer ("MS4") permits, see the 2016 Final Massachusetts Small SM4 General Permit and its appendices, available online at For the Charles River watershed towns, see specifically the requirements for towns discharging into waters with TMDLs – those are found in Appendix F (PDF) (140 pp, 2.3 MB, About PDF).

  3. What sites would be affected by a permit issued under the EPA's RD authority?

    As noted above, the May 9, 2019 petition from the Conservation Law Foundation and Charles River Watershed Association asked EPA to exercise its residual designation (RD) authority to regulate certain stormwater discharges from privately owned commercial, institutional, industrial, and multi-family residential properties that are one acre or greater in the Charles River watershed.

    Note that if EPA grants or partially-grants this petition and makes a residual designation, permits would only be required for otherwise-unpermitted discharges into the stormwater system or directly to waterbodies within the Charles River Watershed. If a property owner already has a stormwater permit (e.g., a MS4 permit, or a multi-sector general permit), it is unlikely an additional permit required through this residual designation process.

  4. What does EPA mean by "impervious cover"?

    Impervious cover generally means surfaces that prevent water from entering the soil and sediment below any site's structures. This can include pavement, rooftops, fountains, and sidewalks.

  5. What are some of the sources of phosphorus in the Charles River watershed?

    In the Charles River watershed (and in many – if not all – developed watersheds around the nation), there are several notable sources of phosphorus, including organic materials (leaves, pollen, seeds), dust and dirt, atmospheric deposition (dry and wet), fertilizers, vehicle exhaust (diesel), and bird waste. Phosphorus can be deposited on a site directly (e.g., fertilizer application), or indirectly (e.g., wind-borne dust from a neighboring lot or particulate pollution from passing vehicle exhaust). When phosphorus is deposited onto an impervious surface like a parking lot or sidewalk, it cannot infiltrate into soil (where it can be used by plants and bound to soil particles); during rain events this phosphorous instead is discharged into surface waters or to local storm sewers and eventually into surface waters like the Charles River.

  6. Is there a difference between rooftop runoff and parking lot runoff in terms of phosphorus concentration?

    The phosphorus concentrations in stormwater runoff from impervious surfaces, are variable regardless of whether it is for roof tops or parking lots. While there are data that indicate certain rooftops may have lower phosphorus concentrations than "on the ground" impervious surfaces like parking lots, these data are not reflective of the universe of rooftop types and the settings in which they exist. For example, rooftops may accumulate phosphorus from birds, deposition of wind- borne dust and organic materials like pollen, seeds, and dust and can accumulate organic materials in gutter systems and become a hotspot for phosphorus. At present, EPA R1 has not seen sufficient rooftop runoff quality data to justify differentiating phosphorus source loadings between rooftops and pavements. However, EPA welcomes the receipt of quality assured stormwater quality data and studies that document roof top and on the ground source areas such as pavement and parking lots.

  7. How does EPA plan to work with parcel owners or other entities that have many non- contiguous locations (e.g., universities with several campuses in different towns)?

    No decisions have been made as to whether EPA intends to grant the petition (in whole or in part) or deny the petition. Decisions regarding how to treat parcel owners that may control multiple sites have also not yet been made. EPA looks forward to hearing more about this potential complicating factor during the stakeholder engagement process.

  8. Will stormwater control improvements I've made recently (or am making now) be 'counted' toward whatever obligations EPA ends up requiring?

    EPA cannot advise entities in the Charles River watershed about capital project planning but notes that no decisions regarding this 2019 petition have been made. Nor has the EPA begun to consider what permits might look like if the agency decides to grant or partially grant the 2019 petition. However, previous actions to control stormwater pollution within the watershed will be considered in any decision EPA makes. EPA is always interested in hearing from watershed stakeholders about their planned investments in stakeholder controls – during this engagement process or during future permitting conversations (should they be needed).

  9. Will the EPA consider nutrient reduction trading if it grants the petition?

    EPA looks forward to hearing from stakeholders on the issue of nutrient trading during this engagement process. This topic may be most relevant for entities with multiple disconnected parcels, or for municipalities that might want to cooperatively invest in stormwater control infrastructure.

Municipality-Specific & Separate Storm Sewer System (MS4) Permit-Related Questions

  1. What role might towns have in either implementing an RD petition or enforcing one?

    EPA looks forward to hearing from municipalities on the role municipal entities may play in any implementation of stormwater controls on private property or any implementation of RD permit requirements for private property owners (should one be needed).

  2. If a town is partially in the watershed, will this affect sites in the whole town or just the sites within the Charles River watershed?

    The EPA's review of the 2019 petition only affects parcels (or parts of parcels) that drain into stormwater systems that drain into the Charles River. If a parcel drains into another watershed, it would not be subject to any EPA decision on this petition. Thus, only the parts of towns with parcels that drain to the Charles River (either through the MS4 or directly) are affected by the present review.

  3. How will this affect the Town's MS4 permit-required phosphorus reductions? Will it reduce the amount the Town is responsible for, or will it help provide additional legal authority for the Town to enforce its current regulations, etc.?

    EPA looks forward to hearing from municipalities on the role municipal entities will play in meeting TMDL goals. Under the current MS4 permit, municipalities need to choose a scope of their phosphorus control plan implementation by June 30, 2022. Each municipality may choose to implement their phosphorus control plan town-wide and assumes the responsibility of achieving the required phosphorus reduction from all sources within their municipal boundaries, regardless of source or whether the property discharges to the MS4 or not. Municipalities also have the choice to implement their phosphorus control plan in regulated area only and can choose to only assume the responsibility to reduce phosphorus in stormwater discharges from sources that discharge to the MS4 system (regardless of source). EPA anticipates engaging municipalities on the impacts of this decision in the coming months.