SEWER NEWS: Understanding CMOM (Capacity, Management, Operations and Management)

CMOM programs are a best practice for sewer line collection system owners and operators. Both comprehensive and holistic, a CMOM provides an information- based plan to effectively run a sewer collection system and help lower the risk of National Pollutant Discharge Elimination System (NPDES) permit violations and discharge violations. The EPA notes in their Asset Management for Sewer Collection Systems fact sheet: “Lacking adequate focus on operations and maintenance, many collection system utilities have slipped into a reactive mode, with most of their operational resources allocated to emergency response and rehabilitation or replacement of failed systems.” Instead, a proactive and even predictive approach is encouraged by following the CMOM program.

In 2005, the EPA published a guide to evaluating and structuring a Capacity, Management, Operation, and Maintenance program. The CMOM approach is not enforced by regulatory authorities, nor is it legally binding, but can be mandated as a response to consent decrees. CMOM program documentation and subsequent audits may also be required when submitting applications for an NPDES permit. The goal of the CMOM process is to assure that discharge from treatment facilities is free from pollutants. Therefore, preventing sanitary sewer overflows, which are illegal under the Clean Water Act, is a priority.

In a CMOM program, emphasizing all four segments equally will reap the most benefits, but the backbone of the program is the management portion. Utility optimization through CMOM programming aims to be adaptable, changeable, and frequently updated, moving away from the traditional long-interval master plans. Therefore, it is difficult to implement a CMOM program without reviewing the internal components of managing a collection system – things like organizational structure and staffing, training and budgeting. An effective management system helps ensure the operations and maintenance portions of the program can fully be addressed.

Collection system operation also supports review, standardization, and transcription of activities and procedures within a department. Proper documentation allows for increased accessibility and accountability with a collection system’s organization. Operators and administrators thus identify and reflect best practices and ensure processes are kept consistent. This information, time and again, proves valuable in the event of an emergency.

The EPA notes some of these responsibilities may include “monitoring discharges into the collections system for individual users; monitoring to determine the effects of sanitary sewer overflows on receiving waters; and recording any sampling that is done, according to the Guide for Evaluating CMOM Programs at Sanitary Sewer Collections Systems. Other operational activities include safety procedures and emergency preparedness and response programs. The EPA guide also lists modeling and mapping under the operations umbrella. New technologies, like tracking with flow rate monitors, are making it easier to create and structure managerial and operational tasks and even automate some maintenance activities.

Operation and maintenance are often grouped together because their activities are so interrelated. The goal is to keep maintenance planned, as opposed to unplanned. Efficient assets have a longer useful life and reduce the likelihood of failure, decreasing emergency response costs. Like other aspects of a CMOM program, establishing written protocols helps standardize procedures and provides data that can be analyzed for patterns and trends.

Ensuring pipelines are prepared to carry the necessary capacity is a complex task. The capacity of a collection systems relies on a number of variables, including the population being served, total system size, and location of house lateral lines. A routine evaluation of capacity can be coordinated in conjunction with the other operations and maintenance activities to round out a CMOM program. Determining capacity requires both testing and inspecting, which largely focus on finding sources of inflow and infiltration (I&I). I&I is a significant contributor to SSOs and CSOs during wet-weather events. Inspections are moving away from confined-space entry methods for the safety of inspection personnel, instead opting for qualitative testing and methods that utilize CCTV inspection technology and collect comprehensive data. Rehabilitation programs are also essential to CMOM and the goals of avoiding emergency situations and staying preventive and predictive.

Implementing a CMOM program is not an easy task. It is both comprehensive and complex but worth the investment of time and resources because the benefits can be felt in both the short and the long term. In the pursuit of increasing efficiency, a CMOM program helps collection system owners and operators identify where the system and the organization as a whole are thriving and what areas need improvement.

Thankfully, the bulk of the work in putting together a CMOM program is to codify and fine-tune existing processes within a collection system. The EPA and other government sources have released numerous resources to assist owners and operators in putting a CMOM program into action. For more information on how to get your municipality’s CMOM program started, go to

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