The Maine Department of Environmental Protection (DEP) is launching the Maine Enterprise Licensing System (MELS), a centralized web-based program for all Water Quality needs. Beginning in mid to late 2027, all Water Quality applications should be submitted through MELS.   MELS will enable electronic submission of incident reports, annual reports, and permit applications, including MEPDES permit renewals, without the need to submit a separate copy with a wet ink signature.    

MELS will improve our service to the regulated community, increase transparency, and make management of Water Quality requirements more efficient.  As registered users associated with a permit or permit application, the regulated community will be able see when an application has been accepted, if corrections are requested, and if the permit renewal is in process.  Once a new permit is issued, an electronic copy of the permit will also be available on the MELS dashboard. To provide input and help shape the development of MELS, please complete the following short survey- MELS Water Quality Survey- by May 15, 2026.

We’ll be in touch again as we get closer to launching MELS for the Bureau of Water Quality. In the meantime, if you’d like to learn more about MELS and how it’s currently being used by the other DEP Bureaus, please visit: Maine DEP: MELS Hub.

For more information, please contact Holly Ireland, Holly.T.Ireland@maine.gov.

This increased circulation disturbs the accumulated sludge and solids that have been lurking at the bottom of the lagoon and pushes them to the surface. This releases hydrogen sulfide (H₂S), the stinky gas that is generated by anaerobic digestion. 

The dislodging of the settled sludge and solids also results in benthal feedback or benthal release, which is when nutrients like nitrogen and inorganic materials like metals that have been trapped in the sludge get released back into the lagoon. Benthal feedback can cause ammonia levels in the lagoon to be higher than in the influent.

Once the temperature hits 50 degrees F or so, bacterial action begins in earnest and starts to consume all the BOD that’s been stored up over the winter. The problem is, aerobic BOD-eating bacteria need dissolved oxygen to work, and there just isn’t enough. In the spring, a wastewater lagoon can need as much as triple the usual amount of DO—as much as 5–6 lbs. of O₂ per pound of influent BOD—to handle the increased load.

Problems Caused by Lagoon Turnover

Without sufficient DO, the bacteria resort to anaerobic digestion, which is a slow and smelly process. Sludge accumulates, odors linger, and effluent violations from undertreatment are likely, including:

1. Floating sludge: As the increasing sunlight and wind circulate the water, the solids settled at the bottom, which have been quietly anaerobically digesting, are churned up. The anaerobic digestion process releases gas as a byproduct, which becomes entrained in the sludge. Once dislodged, the gas trapped in the sludge causes it to rise from the bottom of the lagoon and float.

Figure 2 – Floating Sludge

1. Intense Odors: With the rising gas byproduct of anaerobic digestion, unpleasant lagoon odors are released into the atmosphere all at once. These odors, coupled with those of the floating sludge mat, are strong during lagoon turnover. If picked up by the wind, these odors will likely result in angry calls and a feature story in your local newspaper.
2. Lagoon Treatment Suffers: Lagoon turnover can be a sign that your lagoon is septic and is breaking down nutrients via anaerobic digestion. Expect a spike in effluent BOD, TSS, and other treatment parameters at some point in the near future if corrective action is not taken.

How to Prevent Spring Lagoon Odors

To prevent lagoon turnover, you need to combat the causes:

1. Increase circulation to prevent stratification: By continually circulating the water, the lagoon layers will never be able to fully stratify. With both a homogeneous lagoon water temperature and environment, no spring lagoon turnover will occur.
2. Increase dissolved oxygen levels to combat low DO: One of the easiest ways to do this is to add aeration to your lagoon. By maintaining an aerobic environment you will limit the production of noxious H₂S gases.
3. Increase mixing to prevent sludge buildup on the bottom: Proper lagoon mixing limits sludge accumulation by keeping solids in the water column where they can break down aerobically and odor-free.

Mixing is a critical component of wastewater lagoon aeration, keeping oxygen distributed throughout the water column and preventing solids from settling as sludge. Lagoon aerators that combine efficient fine bubble aeration with coarse bubble mixing in a single portable unit is one way to eliminate floating sludge and odors.

Changes to MEPDES/WDL Application process

When you are ready to renew your permit, you should be aware of changes to the application forms. Please remember that if your permit expires and you have not submitted a complete application for processing prior to the expiration, your facility will be discharging without a license and could be subject to enforcement action. 

Below is guidance to navigate changes to Maine DEP’s MEPDES/WDL application process.

Digital Submissions for Wastewater Applications

The Department is moving to digital submissions for wastewater applications via a designated DEP email site. 

We no longer require permittees to send two print copies to the Department. However, please send one copy with the wet signature page(s) of your application to Laura Crossley, Maine DEP, 17 State House Station, Augusta, ME 04333.

Please also submit your entire application as a single pdf to: WaterPermits.DEP@maine.gov.  If you are unable to access email or lack the online capabilities to complete such a task, please let us know.

Application Form Submission Updates - General Application

There have been recent changes to the General Application.  The updated POTW application has been posted to the website as of April 1. Please use this instead of the EPA Form 2A that we had been using in the interim of the form updates.

All permittees: Complete the updated MEPDES General Application Form.  Be sure to include in your submittal to MEDEP any additional forms specified on page 4 of the application form.

Additional information: Facilities classified as “sludge only facility” that do not discharge to surface waters and “new or existing treatment works treating domestic sewage” must also fill out EPA Form 2S

Concentrated Animal Feeding Operations (CAFOs)

CAFOs must fill out:

1. EPA Form 1; 
2. MEPDES General Application Form; and
3. Microsoft Word - DEPLW0569 - CAFO and Livestock Operation Permit Application.doc (maine.gov)

Overboard Discharges (OBDs)

OBD’s with flow rates greater than 2000 GPD: Please use the MELS Hub to submit your application.  You will need to scan and upload an attachment of the MEPDES General Application Form and EPA Form 2E to the application submitted in MELS.

Note: Always follow MEDEP’s instructions when filling out forms!

Signatory Policy Updates

MEDEP is updating our signatory policies to coincide with 40 CFR Part 122.22, as follows:

• All POTW applications must be signed by an elected Select Board Member, Town Manager or equivalent.
• All non-POTW applications must be signed by an owner, responsible corporate officer, or manager having the duty of making major capital investment recommendations and initiating and directing other comprehensive long-term environmental compliance measures.

More information on signatory requirements for different types of organizations can be found in 40 CFR § 122.22 Signatories to permit applications and reports.

Maine DEP is happy to answer your questions about these changes to the application and submission process. Please contact the Licensing Coordinator, Laura.Crossley@maine.gov, 207-615-6711 to discuss further.

Welcome to Ed Molleo, Maine Water Utilities Association’s (MWUA) new Executive Director!

Ed has previously held pivotal leadership roles in the broad fields of health and safety, largely with nonprofit entities. He has extensive training and experience in communications, strategic planning, emergency operations, and project management. Since 2017, he has held a particular focus on public health — an interest stemming from his personal and academic environmental studies. Prior to MWUA, Ed served as the Director of Communications with HealthReach Community Health Centers, and before that as a key member of both the Maine CDC Public Health Emergency Preparedness and Hospital Preparedness programs.

Ed’s vision for MWUA includes modernizing the Association’s communications; identifying new partners, sponsors, and other stakeholders; and identifying (and meeting!) the unmet needs of Maine’s water and wastewater communities. Working closely in collaboration with both the Maine Water Environment Association (MeWEA) and the Joint Environmental Training Coordinating Committee (JETCC/NEIWPCC), Ed’s goals include raising awareness about water industry career paths, facilitating public education and awareness about all it takes to deliver reliable and safe drinking water to communities, and advocating for water works across Maine with our elected and appointed officials to ensure a considerate regulatory environment.

For more information, visit https://www.mwua.org/ or call 207-623-9511.