Mandy Takes Charge
Crookston Cracks Up
Doug Mandy has taken over as manager of the Minnesota
Department of Health (MDH) Drinking Water Protection Section,
succeeding Gary Englund, who retired last spring. Mandy had
been a supervisor for the noncommunity water program and
more recently for the section’s administrative unit.
Mandy has been an active member of the American Water
Works Association (AWWA) since joining the drinking-water
program at the state in the 1970s. He was the first chair of the
newly formed Minnesota Section of AWWA and also served
for many years as the section’s secretary-treasurer. Mandy
was the 1994 recipient of the Leonard N. Thompson Award,
the highest honor bestowed by Minnesota AWWA.
Despite a landslide that
resulted in a significant
fault line near the Red
Lake River in Crookston,
Minnesota, the city’s
water supply continued
operating. “There’s been
no damage to the
distribution system yet,”
said water superintendent
Perry Hart. “The closest
it [the crack] has gotten is
approximately 25 feet
parallel to a water main.
We’ve shut this main down
and are feeding a few
homes with temporary
lines.” Hart explained that
the U. S. Army Corps of
Engineers was concerned
about the effect of a water
leak to already unstable ground. “Things seem to have slowed
down as far as earth movement for now,” he added. “ We have
the guys ready to shut more valves off if needed.”
Upcoming Certification Exam Dates
March 4, St. Cloud
March 26, Rochester
April 2, Bloomington
April, Southwest Minnesota
April 16, Two Harbors
June 11, Deerwood
See calendar on back page for more details
Winter 2003-04
Volume Eleven/3
Inside:
Dennis Martenson (center) and Warren Schimunek (right) meet
with a citizen at the Minnesota Section American Water Works
Association booth at the State Fair. Once again, the booth’s
drinking fountain, serving St. Paul water, was a popular
attraction, particularly on the hot days. This year, fairgoers
consumed nearly 1,200 gallons (1,196.8 to be exact) of water.
Clara City Reverse-Osmosis Plant
School News
Groundbreaking in St. Paul
Radon Exposure in Water Treatment Plants
Spring 2004 Schools
The 2004 Metro Waterworks Operators School will be held from Wednesday, March 31 through Friday, April 2 at the
Thunderbird Hotel in Bloomington. The certification exams will be held on Friday afternoon. Participants in the school will
receive 16 credit hours for their attendance. The registration for the school is $125 ($160 after March 16 or at the door).
Other spring schools include the Southeast School, March 24-26, Best Western Apache, Rochester; Southwest School,
April (exact date and location to be announced); Northeast School, April 14-16, Superior Shores Resort, Two Harbors; and
Central School, June 9-11 at Ruttger’s Bay Lodge near Deerwood.
MRWA Conference
2004 Teleconferences
The 2004 Minnesota Rural Water
Association (MRWA) Technical
Conference will be held at the
St. Cloud Civic Center from
Tuesday, March 2 through Thursday,
March 4.
For more information, contact the
MRWA office at 218/685-5197 or via
e-mail at [email protected].
The American Water Works Association has set Thursday, March 11 and
Thursday, November 4 as the dates for its 2004 teleconferences. The topic will be a
two-part series on The Future of the Water Utility with one of the teleconferences
covering treatment and the other distribution. The downlink locations serving the
Minnesota Section will be Hennepin County Technical College in Brooklyn Park, the
Minnesota Department of Health in St. Paul, Memorial Union Hall on the campus of
the University of North Dakota in Grand Forks, and Lake Superior College in Duluth,
and South Central Technical College in North Mankato. Participants will receive 4
contact hours. All AWWA members will receive registration information in the mail.
A registration form for the Metro and Southeast schools as well as the March 11 teleconference is on page 7.
The Spring 2004 Waterline will have the entire Metro School agenda with a registration form
that will include the other three-day spring schools.
Coming Down
COMPLIANCE CORNER
Disinfectant Residual Reporting
By Pat McKasy
Beginning January 1, 2004, all community and nontransient
noncommunity water systems that disinfect (chlorinate) must
measure and record the disinfectant (chlorine) residual at the same
sampling points and at the same time as the monthly or quarterly total
coliform bacteria samples are collected. This applies to all water
systems that disinfect (chlorinate), regardless of population or water
source.
The Minnesota Department of Health will provide all of the
certified laboratories in the state with revised bacteriological
result reporting forms, with spaces for filling in the newly
required information. It will be up to each individual laboratory to
decide if it will have its contracted water systems use these forms or if
it will revise the forms it currently uses, adding space for the water
systems to fill in the disinfectant residuals. In any event, the
disinfectant residual readings must be reported to MDH, along with
the total coliform bacteriological sample results, by the tenth day of the
following month (e.g., January results must be reported to MDH by
February 10th). For convenience sake, we are working with private
lab to use them for reporting purposes; however, water systems will
be held responsible for measuring residuals and reporting them.
The smaller water systems (population of 1,000 or fewer), which
have to collect only one bacteriological sample quarterly, will have
revised forms sent to them with their 2004bacteriological sampling kit.
(The kits are typically sent out in December of each year for the
following year’s monitoring.) There will be a space on the revised
form for each system to record its disinfectant (chlorine) residual
reading.
Failure to monitor and/or report the disinfectant residuals is
considered a monitoring violation by the U. S. Environmental
Protection Agency, and a Notice of Violation will be issued to systems
who do not comply with the new rule.
If you have any questions regarding this new requirement, please
feel free to contact Pat McKasy at 651/215-0759 or via e-mail at
[email protected].
2
The city of Cloquet switched water towers in
November, abandoning a 125,000-gallon tank, now
slated for demolition, for a new tower with a capacity
of one-million gallons. Cloquet Public Works Director
Jim Prusak says the bid for the old tower was
awarded November 18, 1907 to Des Moines Bridge
and Iron Works for a contract price of $8,718. While
the old tower had been in service for nearly 100 years,
it almost didn’t make it past the age of 10. A series of
forest fires in October of 1918 included one that swept
through Cloquet; however, the tower survived the
conflagration though much of the city did not.
Minnesota Section American Water Works Association
Annual Conference, October 1-3, 2004, Moorhead
(Clockwise from above left): Ed Sorensen of Eden Prairie receives the L. N. Thompson Award from outgoing section chair Glen
Gerads while AWWA vice president Dixie Fanning greets the recipient of the George Warren Fuller Award, Yasser Abou-Aish of
Minneapolis. The winning TopOps team—Mark Bartholomew of North St. Paul, Jim Heusser of Hastings, and Todd Bredesen of
National Waterworks—show off their winning technique and their prize of $50 each. The arms of Cliff McLain of Moorhead
Public Service and Jennifer Lerdahl of Minnesota Rural Water Association are visible, along with the bodies of two members of
the Line Benders improvisational troupe, the entertainment for the section’s banquet.
Source Water Assessments Now Available on MDH Web Page
Source water assessments are now available online for all
of Minnesota’s public water systems. An assessment
provides a concise description of the water source—such as
a well, lake, or river—used by a public water system and
discusses how susceptible that source may be to
contamination. The types of facilities for which assessments
have been produced range from small businesses on their
own well to large city water systems. Assessments can be
located either by county or by the name of the facility.
Source water assessments are being used in a variety of
ways, including by the public, to understand where their
drinking water comes from; by contamination cleanup
programs, to set priorities and determine the level of cleanup
needed; by permitting programs, to assess if a proposed land
use has the potential to adversly affect a public water supply;
and by MDH, for the purpose of bringing water suppliers into
the wellhead protection program.
These assessments focus on the source of water, rather
than the finished water supplied to customers at their taps.
Source water assessments were created by MDH using
existing data, such as water sampling results,
water system surveys, and well records. For systems using
surface water, the assessment was created in
consultation with representatives from the public water
system.
Assessments are updated as soon as new information
(such as well construction data) is added to the
databases used to generate the assessments. The
assessments shown on the web site are then updated to
reflect these changes.
The assessments can be found at:
http://www.health.state.mn.us/divs/eh/
water/swp/swa/index.htm
3
Clara City Joins the Membrane Wave
Reverse-Osmosis Successful in Removing Nitrite
Along with Rodeberg &
After years of having to supply
Berryman, the city made an
bottled water to pregnant women and
extensive search for another water
families with infants because of nitrite
source with lower concentrations of
in its water, Clara City has taken care
ammonia. Ten separate wells were
of the problem with a reversedrilled at various locations, none of
osmosis treatment plant, the third used
which had sufficient quality or
by a municipality in the state and
quantity for use by the city. Knapper
possibly the first anywhere to use the
said that test drilling done to the east
process for reduction of nitrite. “I had
showed “great water but not enough
no idea of how it would work,”
of it.” In addition, wells in this
said Clara City public works
location would have required a new
superintendent Roger Knapper of the
transmission line.
plant, which went on-line in August
Another possibility considered was
of 2002, “but now we’re producing The Clara City reverse-osmosis system has 72
membrane elements in 12 different housings.
breakpoint chlorination, adding
great water.”
chlorine to the water until the demand is satisfied. Because
Reverse-osmosis was arrived at as a solution only after
of the ammonia, Clara City had been having trouble
the city and its engineering firm explored other alternatives,
maintaining a chlorine residual as the free chlorine converted
ranging from a different source of water to other treatment
to chloramines. Graupman said that adding chlorine to
alternatives, including breakpoint chlorination. A decade ago,
ammonia would cause a reaction that breaks down the
the concept of membrane filtration may have been as
ammonia. “The thought was that if you chlorinated, the
unfeasible as the other options. However, with the cost of
ammonia would be removed and wouldn’t be able to convert
membranes coming down, along with the chemical
over to nitrite.” The problem, he said, was that breakpoint
requirements for such treatment, many see this as the wave
chlorination would require approximately 7 parts of chlorine
of the future, including several other communities in the
per one part of ammonia, too much to make it feasible.
west-central and southwestern portion of Minnesota, where
the search for good water is often difficult.
Solution
With other options exhausted, the city and its engineers
The Problem
made the decision to build a new water treatment plant,
The nitrite is caused by high levels of ammonia in the
adjacent to the existing one, with pressure filters followed by
groundwater, possibly the result of an ancient forest. Knapper
reverse-osmosis treatment. The project would also include
said some of the drill bits used in test borings came up with
a new well, tower, and approximately two miles of additional
pieces of wood, indicating the existence of underground trees
water mains.
that are decomposing and causing the high ammonia.
Reverse osmosis has been used in many ways, including
“The ammonia is causing the nitrite,” said John Graupman,
desalination of sea water on ships. Industries, including
an environmental engineer with Bolton & Menk, Inc. of
bottling companies have also employed the technology.
Mankato, Minnesota, the consulting engineer on the new
“They get treated water from the tap, so they start with fairly
treatment facility, along with Rodeberg & Berryman, Inc. of
consistent water,” Graupman points out, “where we’re
Montevideo, Minnesota. Graupman said the ammonia levels
taking well water—less consistent and a little more difficult
are from 6 to 8 parts per million and that nitrite occurs as a
to handle.”
bacteriological reaction. “It’s almost impossible to stop,” he
The first reverse-osmosis system for a water plant in
explains. “Typically nitrite is not a problem because
Minnesota went on-line in Madison in 1999 to remove
ammonia essentially converts to nitrate. Nitrite is an
sulfate as well as soften the water. Later that year,
intermediate product and essentially because their system
Lincoln-Pipestone Rural Water System completed a
had such low levels of bacteria, it got caught up in an
reverse-osmosis system for nitrate reduction.
intermediate stage. It didn’t convert to nitrate fast enough.
Graupman was the construction engineer for the Madison
“The city tried to clean its lines, thinking that the bacteria
project and says they have learned from this and other
was growing in the lines. They tried a variety of things, but
experiences. “In Madison, the anti-scalants were not very
nothing really had an overall long-term effect.”
advanced at that stage. They also required an acid to drive
the pH down, to keep the scale dissolved. Madison expected
Options
a life of three-to-five years on their membranes and is
The city’s previous treatment had been a gravity filter to
currently just over five years, even with the pre-treatment
reduce iron. It’s sources were a pair of wells at the water
problems that placed an added burden on the membranes.
plant and two others a few miles to the west. The wells at
We’re impressed with how the membranes have worked.”
the plant were low in ammonia but couldn’t produce enough
Compared to conventional treatment, a reverse-osmosis
water to make blending an option. Besides, as Knapper
plant is more expensive. However, with the capital and
explained, the former plant was not set up to run two wells
operating costs coming down, more cities are going with
simultaneously.
4
reverse-osmosis, particularly those in water-challenged
areas. Graupman is involved in the design of two other plants
now under construction—one in Lucan, about 30 miles south
of Clara City, to remove radium and the other in Mountain
Lake in southern Minnesota to reduce sulfate and total
hardness.
Reverse Osmosis
As the name implies, reverse osmosis works against the
natural process of osmosis by using pressure to force water
through a semipermeable membrane that allows water
molecules to pass through, while discharging undesirable
elements, such as nitrate, nitrite, sulfate, hardness, radium,
and arsenic. Put another way, reverse osmosis is essentially
a high-pressure filter that removes contaminants as small as
molecules.
The water pressure is increased to approximately 160
pounds per square inch as it enters the reverse-osmosis
system, forcing the water through the membrane, which
removes up to 99 percent of the dissolved solids, including
nitrite, nitrate, hardness, and sulfate.
The Clara City plant has 12 housings that contain six
membranes in each housing. On the average, each element
produces about three gallons per minute (gpm) of treated
water.
Brian Wise, an application engineering manager for GE
Osmonics of Minnetonka, Minnesota, the firm that installed
the reverse-osmosis equipment in Clara City, explained how
the system works. “Three hundred gpm is fed into the
system. In the first stage, we have six housings with six
membranes in each housing. So there’s 36 membrane
elements in that first stage. So, of the 300 gpm that’s fed into
it, the first stage in total will produce 113 gallons per minute
of purified water. So there is 187 gpm left over of slightly
concentrated water. It’s all the stuff that is rejected from the
membranes.”
From here, the remaining water makes a second pass
through four housings (a total of 24 membrane elements).
This stage produces approximately 75 gallons per minute from
the 187 it was fed, leaving 112 gpm.
“That stream is even more concentrated with rejected
materials—minerals, nitrates, calcium, et cetera. The third
stage, which has two housings, will produce about 37 gpm.
What’s left over is 75 gpm, and that is the final wastestream
that goes to the wastewater treatment plant.”
Along with the contaminants, about 25 percent of the
water (75 out of 300 gpm) is separated and discharged into
the wastewater, leaving the reverse-osmosis system with a
recovery rate around 75 percent.
Wise says they strive to find “a happy medium between
recovering most of what you feed into the system yet not go
too far where your mineral precipitation becomes a concern.
This will affect the life of the membranes.”
Blending is another way of increasing the overall
recovery rate while reducing the burden on the
reverse-osmosis membranes. “Blending reduces operating
costs because you’re not treating 100 percent,” says
Graupman, adding that this also addresses an issue with
corrosion. “If you send out water that it too pure, it tends to
be more corrosive.”
Roger Knapper in the laboratory of the Clara City plant.
Overall Process
Pre-treatment includes chlorine to kill bacteria, potassium
permanganate, polyphosphate as a corrosion inhibitor,
caustic soda, and a polymer to induce a longer run on the
sand filters that precede the reverse osmosis.
An anti-scalant is also added to the water at this point as
a means of protecting the reverse-osmosis membranes.
“When you get scale on a membrane, you can clean it to
some degree, but you run the risk of permanent fouling of
the membrane,” says Graupman, adding that sodium bisulfate is added to remove the chlorine, which will harm the
membranes. “Chlorine is aggressive to the membranes and
attacks them, creating holes, versus traditional fouling, which
is more of a plugging due to scale and other particles.
Fouling can be cleaned to various degrees of success, while
chlorine damage is irreversible. Luckily, the low levels of
chlorine used in the filtration process have little impact.”
All of the water goes through the pressure filters, three
eight-foot diameter vessels about 10 feet tall consisting of
12 inches of anthracite on top of 18 inches of greensand.
Most of the water then goes to the reverse-osmosis
system. Knapper says they normally use an 80-20 blend
although “it may be 85-15 or 90-10.”
The blended water is then treated with chlorine and
fluoride before being pumped into the distribution system.
In addition to bringing the nitrite down to undetectable
levels, the plant has reduced the hardness of the finished
water to between 9 and 12 grains, causing many of the city’s
residents to shut off their home softeners.
The new facility—which includes a laboratory that allows
them to check the levels of iron, manganese, chlorine, and
fluoride as well as the pH of the water—is designed to
operate automatically when the operators are not present.
A computer operating system is used to control the various
motors and equipment and can also be assessed by
computers at remote sites. An alarm dialer is also provided
to call the operators should anything fail with the plant.
In addition to the plant, Clara City built a new 200,000
gallon water tower, dug a new well, and installed about two
miles of new water mains for a total project cost of $3.2
million. The project was funded through a $2.6 million
low-interest Drinking Water Revolving Fund loan and a
$500,000 grant.
Construction began in Fall 2001. The treatment plant and
watermain improvements were completed in the fall of 2002
with the tower completed in spring 2003.
To help pay back the revolving loan, city water rates have
increased from $1.25 per 1,000 gallons to $3 per 1,000
gallons. The surcharge was also increased by $2.50 to $12.50.
5
Radon Exposure in
Water Treatment Plants
St. Paul Breaks Ground
Radon is a naturally occurring gas that
has no color, odor, or taste, and comes
from the breakdown of radium-226.
Radon may be released from areas with
radium accumulation, soil gases, sludge,
or water. It can travel easily through
cracks in concrete or poorly sealed doors,
and it disperses quickly into the
atmosphere. Radon is commonly found
in the basements of many homes in
Minnesota.
Radon may also be found in water
treatment plants that remove radium, and
as a result, water operators may be
exposed to elevated concentrations of
airborne radon within the treatment plant.
The long-term health risk of breathing
radon is lung cancer.
Check Existing Conditions
Water treatment plants should be
tested for airborne radon, particularly if
the treatment plant meets at least one of
the following conditions.
• Open detention tanks, filters,
backwash basins, or clearwells within
the treatment plant
• Backwash waste discharged within
the treatment plant
• Accumulation of radium on filter
media or sludge (producing radon as
a daughter product)
St. Paul Regional Water Services (SPRWS) general manager Bernie Bullert, third
from right, and Maplewood mayor Bob Cardinal, to his left, are flanked by members
of the Maplewood City Council and the Board of Water Commissioners as they
broke ground September 4 for a $12-million SPRWS campus project at the
McCarron’s Water Treatment Plant site in Maplewood to consolidate three separate
sites. The project will bring together the business and engineering divisions, now
located in downtown St. Paul, and the distribution and construction operations,
now in the midway area of the city, with the treatment plant operations. Three new
buildings will be constructed—an office building, a building to house a meter shop
and warehouse, and a garage for vehicle maintenance. When construction is
completed by the end of 2004, the number of employees at the site will increase
from 49 to 238. In addition to St. Paul, the utility sells or directly provides water to
Arden Hills, Falcon Heights, Lauderdale, Little Canada, Maplewood, Mendota,
Mendota Heights, Roseville, and West St. Paul.
Measure Risk
Radon detectors (long-term alpha track detectors) are available free of charge from the Minnesota Department of Health
(MDH) for testing at treatment plants. Two radon detectors should be left in place for at least three months during testing.
These detectors should be placed near each other, at a normal breathing level, away from walls, and in an area where the
water operator spends most of his or her time, such as an office or work area. If the source or treatment plant design changes
in the future, the water system may also want to retest for radon.
If the radon result is less than 4 picoCuries per liter (pCi/L) the treatment plant meets the U. S. Environmental Protection
Agency recommended standard for radon in homes, and the amount of occupational exposure may be limited. If the result is
greater than 4 pCi/L, systems should perform additional testing.
Reduce Exposure
A significant amount of exposure may occur both during the backwash cycle and throughout the day. Below are
recommendations to help to reduce water operator exposure to radon in treatment plants.
•
•
•
•
•
Provide adequate ventilation continuously or when the operator is in the treatment plant.
Use an exhaust fan located directly above the backwash sump during the backwash cycle.
Keep the backwash sump in a well-ventilated room separate from the rest of the plant.
Minimize radium accumulation on filter media by replacing or cleaning filter media.
Limit time spent in the plant during or shortly after the backwash cycle, or use automatic backwash controls.
Contact Karla Peterson, MDH Compliance Engineer, 651-215-0761, or Joshua Kerber, MDH Research Scientist,
651-215-0932, to obtain free radon detectors or information about occupational exposure and additional testing.
6
Waterline
Published quarterly by the Drinking Water Protection Section, Minnesota Department of Health
Editor: Stew Thornley
Staff:
Jeanette Boothe
Dick Clark
Noel Hansen
To request this document in another format,
call 651-215-0700; TDD 651-215-0707 or toll-free through the
Minnesota Relay Service, 1-800-627-3529 (ask for 651-215-0700).
Past issues of the Waterline (in PDF format) are available at:
http://www.health.state.mn.us/divs/eh/water/newsletters.htm
REGISTRATION FORM FOR TELECONFERENCE AND SPRING SCHOOLS
You may combine fees on one check if more than one person is attending a school; however, please make a copy of this
form for each person. Questions regarding certification, contact Cindy Cook at 651-215-0751. Questions regarding
registration, contact Jeanette Boothe at 651-215-1321.
AWWA Teleconference: The Future of the Water Utility, March 14, 2004.
Fee: $65 ($85 after March 4 or at the door) for St. Paul, Brooklyn Park, and Duluth sites; $65 for Grand Forks (no
registration after March 4); $55 ($75 after March 4 or at the door) for North Mankato (no lunch served at this site).
Check location you wish to attend:
____ Minnesota Department of Health Distance Learning Center, Metro Square Annex, St. Paul, Minnesota
____ Hennepin County Technical College, Brooklyn Park, Minnesota
____ University of North Dakota, Grand Forks, North Dakota
____ Lake Superior College, Duluth, Minnesota
____ South Central Technical College, North Mankato, Minnesota
Southeast School, March 24-26, 2004, Best Western Apache, Rochester. Fee: $125 ($135 at the door).
Metro School, March 31-April 2, 2004, Thunderbird Hotel, Bloomington. Fee: $125 ($160 after March 16 or at the door).
Check here if you would like to receive an exam application. (Applications must be submitted at least 15 days
prior to the exam.)
Check here if you would like to receive an exam study guide.
Name
Address
City
Zip
Day Phone
Employer
Please enclose the appropriate fee. Make check payable to Minnesota AWWA. Mail this form and fee to Public Water
Supply Unit, Minnesota Department of Health, 121 East Seventh Place, Suite 220, P. O. Box 64975,
St. Paul, Minnesota 55164-0975.
7
CALENDAR
Water Operator Training
Minnesota Section, American
Water Works Association
*March 24-26, Southeast Water
Operators School, Best Western
Apache, Rochester. Contact Paul
Halvorson, 507-292-5193.
*March 31-April 2, Metro Water
Operators School, Thunderbird Hotel,
Bloomington. Contact Stew Thornley,
651-215-0771.
*April, Southwest Water Operators
School. Contact Mark Sweers,
507-389-5561.
*April 14-16, Northeast Water
Operators School, Superior Shores
Resort, Two Harbors. Contact Stew
Thornley, 651-215-0771.
*June 9-11, Central Water Operators
School, Ruttger ’s Bay Lodge,
Deerwood. Contact Bill Spain,
320-654-5952.
American Water Works
Association Teleconference
March 11, The Future of the Water
Utility, Brooklyn Park, St. Paul, Duluth,
North Mankato, and Grand Forks. Contact Stew Thornley, 651-215-0771.
Minnesota Rural Water Association
Contact Kyle Kedrowski,
800-367-6792.
*March 2-4, Technical Conference,
St. Cloud Civic Center
April 14, Operation & Maintenance,
Elbow Lake
MRWA Training for
Non-Municipal Systems
Minnesota Rural Water Association
April 7, Kasson
April 21, Askov
Hands-On Basic Training for Water Operators
Vermilion Community College, Contact 800-657-3609 or 218-365-7200.
March 9-10—Surface Water
*Schools/meetings marked with an asterisk include a water certification
exam. To be eligible to take a certification exam, applicants must have
hands-on operations experience at a drinking water system.
For an up-to-date list of events, see the training calendar on the MDH web site at:
http://www.health.state.mn.us/divs/eh/water/training.htm
MDH Drinking Water Protection web page:http://www.health.state.mn.us/divs/eh/water
Minnesota Department of Health
121 E. 7th Place Suite 220
P. O. Box 64975
St. Paul, Minnesota 55164-0975
ADDRESS SERVICE REQUESTED