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
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
The causes of sanitary sewer overflows may include
of obstructions in the piping,
infiltration of storm water and groundwater,
and power failure,
and cracked pipes, and
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?
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
Before you can even start looking for funding sources, a
complete survey of the system conditions and needed improvements is imperative.
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
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.
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.
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
Capacity Management Operations & Maintenance Program Will Change the Operation of Sanitary Sewers