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❖ Seal Coating City Streets
LAKEVILLE OPERATIONS & MAINTENANCE
Christopher Petree, Director
July 2010
To maintain a high quality road surface, protecting it from the effects of the weather
and various chemicals is important. Exposure to sun, rain, snow, and salt causes the
road surface to oxidize, lose some of its flexibility. Exposure to automotive oils and
other chemicals causes the asphalt to
break its adhesion with the embedded
aggregate and contributes to a
weakening of the road. The weakening
of the road surface and loss of flexibility
allows cracks to form in the asphalt,
which, without timely maintenance and
repair, leads to complete breakdown of
the asphalt. One method the City uses
to reduce the effects of prolonged
exposure to the weather and chemicals
is periodic seal coating. Roads are
selected for seal coating based on the
pavement condition rating and age with
the goal of prolonging the viability of
the road surface. Seal coating applies an
emulsion of asphalt and polymer that
seals the surface and soaks into the
asphalt to return some of its flexibility.
Granite chips are spread on the
emulsion that bond with the emulsion
to provide a new driving surface. The
addition of the granite chips further
protects the asphalt and is gradually
worked into the road surface. The
granite chips that do not bond with the
emulsion are swept up within a few days and sold for other uses. By monitoring the
condition of the pavement and performing preventive maintenance at the correct
intervals, the City aims to extend the useful life of its streets for many years to come.
❖ Well #2 Production Drop
Over the past two months, staff, monitoring
acquisition (SCADA) system that controls
water production and distribution,
noticed a reduction in the amount of
water produced by Well #2. Some drop
in production during the summer peak is
normal as the water level in the aquifer
drops and the wells work harder to
bring the water to the surface. In this
case, with 2010 being a wet year in
terms of rainfall and correspondingly
low water use that did not seem a likely
explanation. That left staff to determine
if the well was leaking or if there was
some pending mechanical failure. As
production in the well dropped to
about 60 percent of normal, the well
components were pulled to evaluate
the pump, motor, piping, and wiring.
The evaluation of the well
components showed the problem to
be a leaking well. A well leaks when
holes in the pipe allow water to spray
out and run back down the well. The
impact is that production does not
match the effort made by the pump.
Repairing the well involves replacing approximately 230 feet of the piping along with
a similar amount of electrical wiring. Trained and experienced staff were crucial in
finding and trouble shooting the problem before the damage became more
significant.
❖ Fleet Maintenance
Summer is an active time in fleet
maintenance. Activities vary from vehicle
inspections and certifications, daily
equipment repairs, and scheduled vehicle
services to more significant trouble
shooting and major repairs. Recently a
dump truck was brought in for service
because it seemed to be using more oil
than normal. Troubleshooting did not
point to any one cause so the engine was
taken apart to look for scoring in the
cylinders or on the pistons, leaks around
the supervisory
control
and
data
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gaskets, or another cause. From this dissection of the engine, staff localized the
problem to the turbocharger. Before the engine is put back together and tested,
other parts of the engine will also be
checked for wear that may have
contributed to the problem. This is
a major undertaking that staff is
working alongside a variety of other
projects. With the number of dump
trucks in the fleet, having one out of
the line for part of the summer does
not have an adverse effect on
service levels. This truck will be back
in service before snow removal
operations begin.
Just a Quick Sweep
A little known, but
important task that occurs
monthly during the non -
winter months is the
sweeping of gravel off the
asphalt aprons that lead
into grave! roads. Car
tires tend to carry and
spread gravel onto the
aprons and that can
present a hazard to
motorists from the
reduced traction afforded
by the loose gravel. Periodic sweeping keeps the aprons clean
spreading onto the asphalt roads.
and the gravel from
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