For over a decade, U.S. EPA has embarked on a national enforcement strategy regarding combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) from municipal wastewater treatment systems.  As part of the enforcement strategy, U.S. EPA has entered a large number of federal consent decrees which establish deadlines for the elimination of CSOs/SSOs.  These decrees impose costs in the billions of dollars and have compliance schedules that extend over decades.

As part of those decrees, U.S. EPA requires the municipalities to adopt Long Term Control Plans (LTCPs) to address wastewater treatment plan bypasses, SSOs and CSOs.  The standards and deadlines imposed within those LTCPs, in many cases, were based upon U.S. EPA guidance from the 1990s.  

Many national organizations have been sharply critical of U.S. EPA guidance, including:  NACWA (National Association of Clean Water Agencies), Association of Clean Water Administrators (ACWA), Conference of Mayors, National Association of Counties, and the National League of Cities.  These organizations argued the 1990’s guidance was outdated and demonstrated significant flaws once implemented in decrees.

Following an outcry by national organizations for municipalities, U.S. EPA revisited a number of their guidance documents to address concerns raised.  As discussed in detail below, new guidance has been released by U.S. EPA in the following areas:

  • Integrated Planning– The cost of meeting both stormwater (MS4) as well as wastewater treatment system compliance requirements;
  • Affordability-  U.S. EPA’s guidance was outdated and does not allow municipalities to fully present information regarding the impact of increased sewer rates on municipalities;
  • Green Infrastructure–  U.S. EPA has increasingly supported use of green infrastructure (stormwater retention, reduction of infiltration/inflow, etc.)  to reduce the amount of grey infrastructure (storage tunnels, control strategies, etc.)

Integrated Planning

One of the major criticisms of U.S. EPA national CSO enforcement strategy is that it failed to take a holistic look at all the compliance costs faced by municipalities in meeting Clean Water Act requirements. The most significant of those costs relate to stormwater management.  

U.S. EPA finally acquiesced to this criticism allowing cities to evaluate compliance with both wastewater and stormwater requirements concurrently.  U.S. EPA released new guidance titled  “Integrated Municipal Stormwater and Wastewater Planning Approaches Framework.” Memorandum from Nancy Stoner, Acting Assistant Administrator (June 5, 2012)

While the new guidance was welcomed, many municipalities are already under court orders imposes settlements to did not consider integrated planning.  

Affordability

In 1997, U.S. EPA finalized specific guidance on assessing community financial capability
titled- “Combined Sewer Overflows- Guidance for Financial Capability Assessment and
Schedule Development”
. The purpose of the guidance was two-fold: 1) identify the types of financial information that was relevant in determining a community’s financial capability; and 2) establish a specific methodology for gauging a community’s financial capability.

The most important methodology utilized by U.S. EPA to evaluate a community’s ability to afford the controls and schedule for implementing controls in its LTCP is the "Residential Indicator" (RI) factor. The 1997 guidance established the methodology for calculating RI.  

  • Total annual wastewater and CSO control costs per household as a percent of median household income (referred to as the “Residential Indicator” or “RI”)

Despite statements by U.S. EPA in its 1997 guidance and in subsequent communications that RI is but one factor in evaluating affordability, a review of federal consent decrees clearly demonstrates it is the most heavily relied upon factor in establishing compliance schedules.  

Following calculation of RI, the long term compliance deadlines are established based upon whether the community falls into a "low," "medium," or "high" burden community.  

  1. Low = normal construction schedule for all improvements;
  2. Medium = up to 10 years; and
  3. High = up to 15 years and in some cases 20 years depending upon circumstances.

One of the main criticisms of RI is that it tends to washout or dilute the true impact of higher sewer rates on the lower income segments of the community.  RI only utilizes median household income to determine the percentage of overall income dedicated to paying for sewer service.  

On November 24, 2014, U.S. EPA issued new guidance on financial capability assessments- “Financial Capability Assessment Framework for Municipal Clean Water Act Requirements.” Memorandum from Ken Kopics, Deputy Assistant Administrator Office of Water (November 24, 2014).

Under the new guidance, Cities have wider latitude to present information regarding the unique
impacts of CSO/SSO and wastewater treatment compliance costs on the local community.  U.S. EPA argues that the 2014 guidance does not "replace’ the 1997 guidance on affordability, it merely clarifies what was allowable under the old guidance all along.  This statement seems disingenuous given how RI has been directly referenced in a large number of SSO/CSO federal decrees.  

Clearly, the new guidance allows cities to present information regarding the impact of sewer rates on segments of its overall population, including lower income residents.  While the guidance clearly allows such information to be presented, it does not provide an strict guidance as to how much of a burden is "too much" for low income residents.  The lack of clear standards for determining unacceptable burdens on lower income residents further complicates the ability of cities to reopen existing CSO/SSO decrees.

Green Infrastructure

Most early efforts to control CSOs utilized “gray infrastructure” which involves the use of pipes,
sewers, and other structures involving concrete and steel. A very common technique to address
CSOs or WWTP bypasses is the use of storage in tanks, basins, or deep tunnels to store wet
weather combined sewer flows. The wet weather related flows can be held in storage until the
wastewater treatment plan has the capacity to treat the stored wastewater.

“Green infrastructure” (GI) use natural processes to reduce the quantity or rate of stormwater
flows into the sewer system. Common techniques are infiltration, evapotranspiration, and
capture and use (i.e. rainwater harvesting). Green infrastructure can be utilized on a small or
large scale. Small scale techniques include rain barrels, bioswales, porous pavements, green
roofs and infiltration planters. Larger scale techniques include wetlands, riparian buffers, open
space or other techniques involving larger tracts of land.

U.S. EPA has increasingly supported the use of green infrastructure to address CSOs and wastewater treatment plant bypasses. October 2013, U.S. EPA Headquarters released the Green Infrastructure Strategic Agenda which directs EPA enforcement personnel to:

  • “Ensure all water enforcement actions consider the use of green infrastructure;” and
  • “Consider green infrastructure approaches in the development of orders and settlements
    related to SSOs, CSOs and MS4s and incorporate green infrastructure as part of
    injunctive relief were appropriate.”

U.S. EPA released additional green infrastructure guidance titled “Greening CSO Plans: Planning and Modeling Green Infrastructure for Combined Sewer Overflow (CSO) Control.” U.S. EPA Publication #832-R-14-001 (March 2014).  The new guidance strongly encourages incorporation of green infrastructure into LTCPs.

While U.S. EPA has moved aggressively toward encouraging uses of green over grey infrastructure, many decrees predated the most recent information on the benefits of green.  Cities that have LTCP that almost exclusively rely upon grey infrastructure will need to make detailed demonstrations that green approaches are equivalent if not better than existing grey infrastructure. 

Re-opening Existing SSO/CSO Consent Decrees

With all the new guidance that has been released since 2013, many municipalities who have been under existing decrees rightfully question whether they have an ability to revisit their settlements. U.S. EPA indicates that it is willing to revisit settlements:

  • U.S. EPA states that remedy and affordability determinations under existing decrees can be reexamined under EPA’s new Integrated Planning Approach.  EPA states such requests must be supported "with sufficient information and analysis to determine whether an Integrated Planning Approach makes sense based on sound science and appropriate technical and financial analyses." (See, Integrated Municipal Stormwater and Wastewater Planning Frequently Asked Questions (July 25, 2013))

However, the practical reality is that cities will be required to continue to comply with their existing LTCP while concurrently generating new extensive studies to support reopening their existing decree.  Most decrees also require the municipality to petition the U.S. EPA first before requesting that the court intervene. 

In addition, as highlighted by the City of Akron’s recent inability to reopen its CSO decree citing new U.S. EPA guidance, cities face significant challenges.

Nevertheless, U.S. EPA has issued so much new guidance and strongly indicated a willingness to revisit existing settlements, it will be very difficult for the Agency to not acquiesce when cities present a legitimate request that is well supported using the new guidance.  

It will be interesting to see how EPA handles these requests in the next few years given what is at stake in terms of compliance costs.