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MetCom Staff Recognized for
Environmental Improvements
The management of the St. Mary's
County Metropolitan Commission (MetCom) would like to recognize the
efforts of several groups of employees within the organization.
Through their efforts the citizens of St. Mary's county can rest
assured that every effort is being made to protect the local
environment from Sanitary Sewer Overflows (SSOs). SSOs are
accidental or unintentional releases of sewage from the pipes and
pump stations used to collect and convey sewage to the treatment
plants. These efforts have met with great success resulting in a
significant reduction in the number and severity of preventable SSOs
occurring from MetCom facilities. SSOs are prohibited by regulation
because they allow untreated sewage to be discharged into the
environment which can have a detrimental impact on public health.
Preventable SSOs are events that can be eliminated by effective
maintenance of the infrastructure used for collection and
conveyance.
Setting Goals
A goal of the Maintenance Department
has been to go one full year without having a preventable SSO.
Recently the department got within ten days of achieving this
objective. The Maintenance Superintendent is not discouraged by
this, but is even more determined to make this goal a reality. In
spite of this recent shortfall, MetCom has achieved a significant
reduction in the number of SSOs as a result of this goal and the
efforts of the staff members responsible for achieving this goal.
The following graph shows the reduction in preventable SSOs between
2000 and 2005. This reduction is a result of the efforts put forth
by a majority of the staff and has done much to protect the
environment and public health of the citizens in St. Mary's County.
Inflow &
Infiltration
Large amounts of Inflow & Infiltration
entering a system can exceed its capacity and result in an SSO.
Inflow is rainwater that gets into the system and infiltration is
groundwater that enters the system. Both enter the system through
failed joints, cracks in the pipes, or intentionally by illegal
hook-ups of sump pumps, drains, and rain spouts to the domestic
sewage system. MetCom's Inflow & Infiltration staff uses modern
equipment to inspect and monitor the system to identify potential
and existing problems that contribute to these accidental releases.
This equipment includes special television cameras that are inserted
into the pipes so that technicians can actually see the condition of
the pipe's interior. These televised inspections are taped and
reviewed by staff to determine what repairs or maintenance are
required to correct problems identified through this process.
Another device generates smoke and forces it into the collection
system which provides a visible indication of the sources of water
entering the system from the ground surface or downspouts. Special
portable meters designed to be inserted in sewer lines are used to
collect flow information which is added to similar information
collected from pump station meters to determine total flow volumes.
These measurements are checked during low and high groundwater
seasons to determine infiltration and during and immediately after
rain events to determine inflow. Computer programs are used to
compile and analyze this data to establish needs and set priorities
for further inspection, repair, and/or replacement of system
components.
Sewerline
Maintenance
Equipment failures at pump stations
and blockages in sewer lines can be caused by debris that builds up
in the system. This debris can be sand, rocks or grit, grease or
scum, and other objects like paper, cloth, plastic, or wood that end
up in the sewer system. Roots from nearby trees can cause blockages
by growing inside the pipe and obstructing flow or damaging pipes
when the root growth forces open joints or cracks in the pipe.
MetCom's Sewerline maintenance staff works diligently to insure
debris build up and root intrusions don't contribute to causing an
SSO. The Sewerline crew has two large combination Jet-Rod-Vacuum
trucks that are used to maintain the sewerlines and the pump station
wetwells. These trucks can vacuum material from the bottom of
wetwells or manholes and remove it from the system. The Jet-Rod is
basically several hundred feet of high pressure hose that is fitted
with special nozzles that serve to propel it through the pipes and
break up any debris blocking the pipes. One type of nozzle used is
designed specifically for cutting roots and has revolving blades
that are turned by the water pressure as it moves through the pipe.
The debris or roots that are loosened by the Jet-rod are washed back
to the manhole and vacuumed up into a tank to be transported to the
treatment plant for disposal. Sewerline maintenance technicians
work very closely with the Inflow & Infiltration crew to insure that
the pipes in the system remain free from blockages by following a
rigorous maintenance schedule. Every sewerline in the system is
cleaned at least once each year and problem areas are cleaned more
frequently. The frequency of cleaning has been established based on
historical data and the information gained through the television
inspection program.
Mechanical
Maintenance
All mechanical equipment in the
collection system receives regular maintenance from the Mechanical
maintenance crew to insure the reliability of the system. Nearly
all of the wastewater pump stations have emergency generators to
provide power during electrical outages. Some newer stations are
being designed with back up diesel engine pumps instead of
generators to allow a back up for pump failures caused by electrical
outages and mechanical or control problems. A computerized
maintenance management program tracks all repairs and equipment
histories and generates work orders for preventive maintenance task
required. The Mechanics closely monitor the preventive maintenance
program to insure it is effectively protecting the operating
equipment and look for ways to improve the function of existing
equipment. The group also has access to a number of local contract
vendors and specialist who can economically and quickly provide
support to solve the more complex problems that require special
tools or training. This group utilizes a preemptive response to
severe weather events that has significantly improved the systems
ability to survive these events while protecting the environment.
System
Operators
All water or wastewater system
Operators are required by Maryland regulation to be certified. The
Operators that monitor the wastewater collection system are all
fully certified and have many years of service to this
organization. They are out in the worst weather conditions checking
on these stations to insure they operate continuously throughout the
event. They rotate being on call to insure that potential problems
are quickly checked and resolved. MetCom has been installing
Supervisory Control and Data Acquisition (SCADA) equipment as part
of a multi-year project in its water and wastewater pump stations.
About 25% of the wastewater stations are currently equipped with
SCADA which uses radio signals to transmit information back to a
computer in the main office. The operators use Lap-Top computers to
monitor the activity at these stations to insure they are operating
properly. The remaining stations have Automatic Dial Alarm Systems
(ADAS) that use telephone lines to communicate information back to
the main office. During the off hours these calls are answered by
the Emergency Control Center operators in Leonardtown who notify
MetCom's stand-By operator of the problem. When call volume
increases due to area wide problems these calls are transferred to a
Stand-By Dispatcher who will take the calls and relay the
information to the operators. Operators must respond quickly to an
alarm to assess the situation and correct the problem or notify the
appropriate support staff to make a repair. The Operators working
for MetCom are very conscientious about their duties and are the
first line of defense against problems at the stations that could
lead to an SSO.
Construction &
Engineering
MetCom has one Construction crew that
is backed up by a contractor when the workload is excessive or more
complicated repairs are needed. The Construction crew works to
repair water main and sewerline breaks and are many times working in
adverse weather conditions. They must respond to emergency
situations regardless of the time and the conditions where the
repair is needed. They have made many of the repairs identified by
the Inflow & Infiltration crew to stop excessive flows from entering
the systems. Many of these repairs are simple pipe reconnections
but many times they have tackled complex jobs like replacing entire
manhole structures. They are a very professional group that
responds immediately to a problem and have the experience to make
effective repairs quickly and efficiently. They are supported by
the Engineering and Construction groups who supply them with the
technical information and location services they need to accomplish
their mission. The Engineering group also provides support to the
Inflow & Infiltration staff to design solutions to major problems
found in the field. This support ranges from simple recommendations
to completing or commissioning the completion of complete system
replacement projects. They provide a necessary service that insures
the systems will function as planned which reduces the potential for
problems that could have negative impacts on its operation.
Administration
& The Team
The Administrative and support staff
also plays a significant role in the improvements noted in this
organizations ability to protect the environment. They insure
funding is in place and that contracts are available for the tools,
supplies, and support services needed to deal with many of the
situations discovered in the field. They maintain the computerized
programs and record systems utilized to effectively manage MetCom's
sewerline programs. They provide dispatching functions on a daily
basis and are particularly active during severe weather events.
They insure that the groups are staffed with qualified people and
that they receive the training needed to maintain their skills and
knowledge. The Administration group helps tie it all together and
allows the team to function effectively. This accomplishment has
not been the result of any one group within the organization, but is
a truly collaborative effort by all of MetCom's employees. The
customers of this Commission and all of the citizens in this county
benefit from the efforts of this team called MetCom and the staff
here are dedicated to serving you to the best of their ability.
William A. Shreve
July 6, 2006
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