CMOM is the acronym for the new Capacity, Management Operation and Maintenance program that soon will be enacted by the U.S. Environmental Protection Agency (EPA). In its simplest form, it has to do with the operation of sanitary sewers to prevent overloading of waste treatment plants and the overflow prevention of sanitary sewage into lakes and streams.
For many years, the natural inclination has been "if waste successfully comes in one end and out the other, don’t worry." With the Clean Water Act, among other things, came the prohibition of untreated sanitary waste overflow. Residents have been increasingly upset when sanitary sewage backs up into basements.
General lack of attention to sewer systems partially is due to despair over funding and a general lack of political drive to invest in the upkeep of sewers and waste treatment facilities. By the time the problems become chronic and the ensuing consent decree is issued, the costs may be enormous.
EPA now points to substantial fines that have been leveled against sewers and the fact that almost all beach closings nationwide have been due to spills. The bottom line, according to EPA, is that systems are going to have to adopt a more proactive approach, and CMOM is the "sewer system business plan."
The CMOM Plan
EPA is concerned that many sanitary sewer systems are inadequate to handle current flows, and at times there are overflows and spills during normal operations. EPA regards this situation as an unacceptable public health threat.
The causes of sanitary sewer overflows may include
-- System deterioration,
-- Build-up of obstructions in the piping,
-- Excessive infiltration of storm water and groundwater,
-- Pump and power failure,
-- Broken and cracked pipes, and
-- Undersized piping.
The plan has been described as a "consent decree" that you write for yourself. On the one hand, spills are outright prohibited. On the other hand, knowing their inevitability, EPA states that a potential post-spill enforcement action will consider the following: Do you have a CMOM plan in place that represents "best practices" in all areas? Does your plan demonstrate a true commitment to stopping overflows? Are you following the plan? If the answers are all positive, the outcome will be more "favorable" to operations.
As currently proposed in the CMOM rules, all sanitary sewer collection systems will be required to have their own NPDES permit. This includes "satellite collection systems"--systems that only convey wastewater and do not have their own treatment plant. Two or three years after the new rules are finalized, collection system owners will be required to apply for the permit, unless they have a sewer overflow or basement backup incident in the interim. If they do have such an incident, they will have to apply for their permit within six months.
The Present Situation
The proposed CMOM rules have gone through one informal review. EPA currently is addressing the comments received on the original version, and it is expected that the draft "Notice of Proposed Rulemaking" will be printed in the Federal Register in the Fall 2002. At that time, the official public comment period begins, which probably will extend for approximately four months. After the public comment period closes, EPA will develop a final rule package. How long it will take before the final rule is promulgated will depend in great part on how many changes will be required in response to the public comments.
Although there will be various changes in the final rule, there is no doubt that the new rules are coming, and the general intent basically will be the same as it is now. Several states already are moving ahead with their own CMOM regulations that should dovetail final federal requirements. A proactive approach now will provide operators with more time to develop a reasonable program and response.
Where Do We Start?
-- Funding--EPA estimates that this rule will impose an additional total cost for all municipalities of between $93.5 and $126.5 million each year. For a collection system serving a population of 7,500, they estimate the average additional cost for complianceat about $6,000 each year. These costs do not include the cost of repairing or upgrading existing sewers to meet Clean Water Act requirements. So, if the system is old and neglected, you might be facing hefty improvement costs.
Before you can even start looking for funding sources, a complete survey of the system conditions and needed improvements is imperative.
-- Mapping--What do you have in the ground? If your collection system is current, you have a head start. If it is inaccurate or you are not sure, bring it up-to-date. If a map is non-existent, it is the first step.
A suggested way of checking map accuracy is to inspect every manhole and identify every pipe that enters or leaves. A pipe locator with sonde is the ideal method of identifying unknown pipe. The sonde, strapped to a sewer rod end, is a miniature transmitter that communicates with the surface locator unit via a unique frequency.
-- Illegal Connections--In most sanitary sewer systems, the biggest contributors to excessive flow during rain storms are downspout, sump pump and area drains that quietly were connected by residents. If you already have surveyed the system to identify and disconnect these storm water sources, you have a head start. If you have not, you had better start planning.
Suspected downspouts can be checked by pouring dye at the source and observing downstream manholes to see if it passes. The fastest method is smoke testing. If your testing program is well-organized, an experienced crew quite possibly can test a small system in a matter of days. At the same time, it also will identify some broken pipes, leaking manholes and other sources of storm water inflow.
-- Pipe Condition--Unless a collection system is brand new and perfectly installed, it almost is essential to do a television inspection of piping. Broken pipes, leaking joints, protruding lateral connections, globs of roots and a variety of other items will be encountered.
TV inspection can be done by specialized contract firms, but the cost of good, portable TV inspection equipment has become so reasonable that many systems are now buying their own. An advantage of ownership is that it readily is available anytime. A sudden blockage can be examined and diagnosed prior to digging.
The TV inspection will, of course, identify most of what you are going to have to do. Some locations will require digging and repair. Other whole sections of pipe require lining or laying new pipe. WWD