HomeMy WebLinkAboutItem 05Public Works
May 2013
Positioned to Thrive
Roof Top Unit (RTU) Replacement
Two of the roof top HVAC units at City Hall
were recently replaced with new, high
efficiency units. The two replaced RTUs were
original to the building and had suffered
several key component failures in the past few
years. On one of the seemingly few sunny
days this spring, crews blocked off the City
Hall parking lot in front of the building,
disconnected and removed the old units,
hoisted up a curb adapter and then placed the
new units. A curb adapter was necessary
because the foot print of the new units is
significantly smaller than the old units though
they are similar in cooling
capacity. In terms of
efficiency, the new units
have energy efficiency ratios
(EER) in excess of 11.0,
whereas the old units had
ratings of approximately 8.9.
The EER measures the
relative efficiency of a
heating or cooling appliance,
the higher the number the
more efficient the appliance.
The new RTUs were
operational within a few
days of their installation.
LAKEVILLE PUBLIC WORKS
Christopher Petree, Director
May 2013
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❖ Generator Upgrade
During this past week, the exhaust system for
the Water Treatment Facility's generator was
refitted with an oxidation catalyst system to
reduce the emission of hazardous air
pollutants. This upgrade is in response to the
recent finalization of the Environmental
Protection Agency's (EPA) emission
standards for diesel engine generators.
Known formally as the National Emission
Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal
Combustion Engines, the standards require
users of diesel generators over 500
horsepower to quantifiably reduce
hazardous emissions. The installation of the
oxidation catalyst is just the first step, albeit
the largest, in the process.
Once the catalyst is installed,
the generator's emissions
must be tested regularly for
compliance with the new
emission standards. Results
of testing are sent to the EPA.
A second generator at the
Central Maintenance Facility
is being upgraded this week.
These generators are used as
emergency backup power for
these facilities and also for
peak shaving by Dakota
Electric Association.
+ Sod Replacement
In typical snow and ice control
operations, the goal is to clear the
entire pavement surface, from curb to
curb. Most of the time that is exactly
what happens, but roads are not
straight and there are any number of
external forces acting on the truck as it
turns corners and moves around cul-
de -sacs. As a result, a plow will
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occasionally ride up the curb and damage the sod along the boulevard. Areas with
damaged sod are logged and the sod is
replaced in the spring. Replacement
dates vary depending on when the sod
farms have sod available. But, before
the sod is replaced, crews go out and
prep the areas. This means removing
the damaged sod and prepping the
area to receive the new sod, and
cleaning up the old sod. Crews are
working throughout the City to prep
damaged areas and will be following
up with new sod shortly.
Erosion Control
Over the past month, the
Environmental Resources staff
has been active in inspecting
residential construction
projects for compliance with
the City's erosion control
ordinance. The purpose of the
erosion control is to keep
sediment laden storm water
runoff from entering nearby
bodies of water or
depositing sediment on
adjacent properties. Each
project is required to have a
drainage and erosion control
plan that meets the
standards under the National
Pollutant Discharge
Elimination System and the
corresponding state
program. Since the
beginning of May, 82
inspections have been non-
compliant. Once given notice of non - compliance, the builder has 72 hours to
become compliant. If the site remains non - compliant after 72 hours, the City can
then withhold building inspections, but allow work to continue, or issue a stop
work order, stopping all work on the project. Of the non - compliant inspections, a
majority are in the process of being re- inspected.
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Hydrant Flushing
The Utilities Division maintains
over 3500 hydrants and
annually exercises each of
those hydrants. Originally,
this was done primarily as a
means to evacuate sediment
from the water system. Now,
since Lakeville's treated water
results in significantly less
sediment in the water system,
hydrants are exercised to
ensure their operation in an
emergency. All of the caps are
removed and lubricated so
they do not bind and the valve is opened to allow full water flow and then closed
again. Water from the hydrant is run through a diverter attached to a pickup truck
and discharged into the street. Use of a diverter helps ensure that the green space
around the hydrants is not damaged by the water flow. Hydrants that are difficult
to open are noted and repaired. Crews will be out throughout the summer until all
of the hydrants have been exercised and repaired.
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