Kip Hill (816)550-6877COLUMBIA — The city’s Grissum Building will be receiving a
makeover to study the effectiveness of several stormwater treatment and runoff reduction
installations as part of a nearly half million dollar project coordinated by the city and
Boone County.
The building, which is used for the Public Works Department’s solid waste operations,
has been selected as a test site for six retrofit projects to reduce stormawater runoff and
filter contaminants to the Bear Creek watershed. The construction will be partially
funded by federal grant money obtained by the county
(http://www.columbiamissourian.com/stories/2011/02/17/stormwater-grant-aid-hinksoncreek/) for the purpose of improving the water quality of Bear and Hinkson creeks,
according to a report issued by Columbia’s Public Works Department (link to report).
Hinkson Creek has been listed as an impaired body of water by the EPA since 1998, due
to amounts of pollution in excess of agency regulations, known as the Total Maximum
Daily Load (TMDL).
Last January, the EPA issued recommendations that the city and county take steps to
reduce stormwater runoff to Hinkson Creek by 39.6 percent, including the use of several
treatment and runoff-slowing installations such as those being installed at the Grissum
Building (http://www.columbiamissourian.com/stories/2011/01/31/epa-issuesreccomendations-clean-hinkson-creek/). Citing high costs and incomplete data, the
Missouri Department of Natural Resources, the city and county moved forward with their
own plan in August to examine other sources of pollution for both creeks and the most
effective method to improve their water
quality(http://www.columbiamissourian.com/stories/2011/08/04/dnr-hinkson-creek-planignore-epas-tmdl/). The Grissum project is intended to provide this data and determine
the effectiveness of each installation to improve the condition of all area watersheds, Erin
Keys, an engineer for the city, said.
“Even though the property is in the Bear Creek watershed, it will be useful for all
watersheds in the area,” Keys said. “It’s important to protect all of our watersheds, not
just Hinkson Creek.”
The agreement calls for the construction of several Best Management Practices (BMPs),
or installations designed to reduce pollution and erosion. These include two rain gardens
in the southwest corner of the Grissum site, porous pavement that would filter rainwater
seeping into the ground, a series of stormwater conveyance pools to the north which act
as a way to slow and treat fast-moving runoff and numerous bioswales in the north and
east portions of the site. Bioswales are sloped landscape elements designed to trap water
pollution.
Keys said the construction projects will not impact operations of the Grissum Building or
the participating agencies, including the Water and Light and Parks and Recreation
departments.
The city will pay more than $250,000 for the construction of these installations and to
communicate the findings of the pilot program to area engineers and developers. The
county will add to that sum more than $210,000 of grant money from the EPA over the
length of the project.
Georgeanne Bowman, stormwater coordinator for Boone County, said that the
conveyance and bioretention systems should be completed by the end of the year, and
that construction of the porous pavement, rain gardens and other installations will begin
next year. The agreement charges the county with collecting data and monitoring all
installations on city property.
Bowman said pollution levels and runoff flow speed will be collected through two sigma
samplers. Runoff flows through the sampler and once a threshold of flow speed is
reached, the device begins collecting samples. Two of these devices will be used at the
Grissum site, and will be rotated to the next available installation once data collection is
complete, Bowman said.
The county pledges in the report to publish findings related to runoff management in
December 2013. Bowman said measurement of 20 significant rain events for each
installation would be ideal and that the timing of a final report would be contingent upon
the weather.
“If we have rainfall like 2008 and 2009, we’re going to be fine,” Bowman said. “If we
have rainfall like last year, we may have a problem.”
The idea of a step pool conveyance system came from a study in Maryland. The structure
will treat polluted runoff from both the Grissum site and the adjacent power plant, Keys
said.
Bowman said the data collected at the Grissum site will add to studies conducted on the
East Coast about the effectiveness of each installation.
“For Missouri, there’s no BMP data,” Bowman said. “We’re trying to change that.”
In addition to providing data for future stormwater management projects, the report notes
the work at the Grissum Building will bring the site up to the standards of the city’s
Stormwater Management and Water Quality Manual
(http://gocolumbiamo.com/PublicWorks/StormWater/documents/2008manual.pdf).
Keys said the Grissum site has no stormwater retention or treatment facilities. The
requirements of the city manual must be followed only when redevelopment of a site
occurs. The federal money will allow the site to upgrade even though it’s not required by
city ordinance, Keys said.
At the same time the city retrofits the Grissum Building site, the county will be
conducting a similar study in the Sunrise Estates subdivision about five miles east of
downtown Columbia on Interstate 70.
Bowman said the subdivision has had major problems with stormwater over the years as
the homes were constructed before runoff ordinances were passed. After securing the
federal grant last year, Bowman said the homeowner’s association responded
enthusiastically to participating in the program.
“They were extremely ecstatic,” Bowman said. The county will handle all costs, data
collection and management of the Sunrise Estates project.
Following the completion of both projects, the city and county pledge to conduct a widereaching public outreach program to share findings. The campaign will specifically target
developers, engineers and builders as they move forward on construction projects within
both the Hinkson and Bear Creek watersheds. Keys said she hoped information about the
cost-effectiveness and feasibility of the installations on an already-developed site would
encourage further adoption of the practices.
“Stormwater BMPs are kind of like a mosaic,” Keys said. “One little tile by itself doesn’t
mean a whole lot, but when you put them together they make quite a picture. The bigger
picture is much improved water quality for all of our local creeks and watersheds.”
Keys 573-874-7217
The report mentions the Grissum Building is not currently up to the standards set forth in
the city’s stormwater management manual, which I’m assuming is section 6.8.1, water
quality for previously developed sites. What does it need to bring it up to these standards?
Any specific kind of BMPs? Is it a level of pollution? Are there a lot of buildings in the
Hinkson and Bear Creek watersheds that are currently not up to these standards?
The stie doesn’t’ currently have an ys tormwater bmps on it. Like any site, none of those
stormwater sites have any bmps either. When someone comes in and wants to develop a
piece of property, they have to install the bmps. When you redevelop a piepce of
property, you are required to install a BMPs.
It’s an opportunity to bring these sites up to current with our stormwater manual even
though we’re not required to do so. Part of the grant is to monitor the BMPs, and the
information that we get from that we’ll be able to provide to local developers and
engineers, so that when they go to retrofit a development that they’re involved in they’ll
know which work better than others and provide a certain level fo service.
Couple of quick questions about funding. As I understand it, the matching funds are the
maximum amount that will be provided by the city, correct? These estimated costs are
values up to which the county will pay for installation, and all other costs will be covered
by the city?
3 year project we’ll see how we’re doing after the first year.
Will the construction of these BMPs at the Grissum site impede the operations of that
building in any way?
This is, obviously if it snows, that’s a priority. That’s what will be rtaken care of. The
winter is a little bit slower time of year. There’s a lot of maintenance that needs to be
done. A water and light crew will be helping, and parks and re is contributing. Everyone
that’s working on it is fitting it in between their duties. Water main breaks. This is getting
worked in as time and equipment is available.
The BMPS are, one fot he BMPs will also help treat the water that comes off the power
plant. The step pools will treat the water from both sites. Most other bmps are directly
related to the Grissom site.
How closely will you work with the county public works department on this project? Any
additional meetings?
That’s something that GeorgeAnne would be more familiar with. I know that we plan to
share the information that we gather with the local community. We do plan to have a
website, I’m afraid I don’t know of the thing off the top of the head. There will be a
project website.
How important is this educational outreach program at the conclusion of data collection?
Will this be something that will be a feature of the city website, in addition to the signs
and other forms of publicity mentioned in the report?
That’s what we’re trying to do, is point out that these retrofits are possible in any kind of
facility. We have a completely developed pieces of ground that we’re installing these
retrofits. We want to find out how cost-effective these are. See how close we got to our
estimate. By fmonitoring them, we’ll know effective.
Stormwater BMPS are kind of like a mosaic. One little tile by itself doesn’t mean a whole
lot, but when you put them together they make quite a picture. The bigger picture is much
improved water quality for all of our local creeks and watersheds.
Part of the grant was to get a residential property, and we’ve got kind of an industrial
which you could extrapolate to a commercial picece of property. It didn’t require a lot of
easements. Even though it’s in the Bear Creek watershed, the data will be useful for all
watersheds in the area. It’s important to protect all our watersheds, not just Hinkson
Creek.
Joe Engeln MDNR Watershed Protection Program MDNR Number
Amanda Sappington, Environmental Specialist
How important is this step in moving toward complying with the EPA requirements?
Will this project provide the kind of data the department, city and county were looking
for when they questioned the priorities of the EPA runoff regulations several months
ago?
How important is public outreach in a program to clean up the watershed? Do you
believe enough has been done to inform the public and business owners who live in this
watershed about nonpoint pollution?
What would be the ideal outcome of this project? In other words, what data are you
looking for, and what would the education phase of the project look like, ideally?
Found out about from Maryland.
Step pool conveyance — A series of shallow pools, with a gravel or woodchip bed, that
filter out pollutants in stormwater runoff and slow the flow into the ground. Creating
pools and riffles in a very short area, so it will go from one pool and it will have to
overflow that, each time water hits water, you take out a lot of the velocity. We’ll use
mostly rocks and gravel. The woodchips would put nutrients back into the water. We
need inert stuff.
Bioretention — The planting of native vegetation in specific soil designed to trap
pollutants as stormwater seeps into the ground. Kind of like a rain garden, except it will
have a filter in the bottom of it. You excavate a hole and you put ina better mix of soils. If
you dug out a hole, all you’re just making a pool. There’s a filter in the bottom of it.
Filter and the outlet structure. A pipe that will let the water flow through the BMP.
Bioswales — A sloped channel, containing plant life, that slows the flow of stormwater
runoff and traps pollutants as the water flows through the channel.
Pervious Asphalt — Porous pavement that allows stormwater to filter through, as
opposed to traditional pavement that simply runs off. Designs for the Grissum site have
the stormwater being detained from the pervious asphalt in an underground detention
area.
Rain Gardens — Prairie and wetland vegetation is planted in a small depression on the
site, where runoff collects and pollutants are gathered by the roots of the plants. The
city’s stormwater guidelines note that these gardens are primarily used in residential
areas.
Underground Detention — Below-ground reservoirs designed to store runoff and allow
for slower absorption into the ground, lessening the possibility of flooding. The design
for the Grissum site places an underground detention facility beneath the pervious asphalt
just south of Sims Street.
Is there any indication of which has worked best in the past, or is it a kind of case-by-case
thing?
Tger’s a lot of research that’s been done on the East Coast. But they have a lot different
soils. They have a lot more sands in their soils and they’re rainfall patterns are different.
For Missouri, there’s absolutely no BMP data. We’re trying to change that. How can we
justify putting these structures in for our clients if we’re not sure it’s going to work at all?
Pilot program to determine, we have a long way to go.
Boone County, GeorgeAnne Bowman 573-886-4489
What will the data collection process look like at the Grissum site? Has this type of datacollection program been done before?
Not around here. We got a 713,000 grant from DNR last March. We’ve been trying to get
piece of this into play since then. This is a two-part project. The grissum building they’re
going to put in at least 6. Three this year by August. The first one we’ll be doing is a
bioretention cell just north of one of the parking lots. Then we’re going to be doing a step
pool conveyance system on the Water and Light property. Right now they’re two pipes
and a roadless ditch. We’re going to put a structure in to dissipate the energy and stop the
erosion. Pervious pavement is third. Rain gardens.
On the bioretention, the first that we’re going to do. We’re going to put in two water
samplers. Sigma samplers. Automatic samplers, once a certain amount of flow is
recorded, it will start sucking up some of the water in to the tubing. We’ll do that as the
water runs off the parking lot, so we can figure how much pollutants are in the parking lot
water and we’ll collect it at the other end of the BMP. We’re schedule to sample at least
20 events. It will collect the water inside the vials. We’ll take them to a lab and have
tehm sampled for pollutant.
If we have a rainfall event like we had in 2008, 2009, we’re going to be fine. If we have
one like last year, it’s going to be a problem.
Once we hit 15, we might go ahead and move it. I think we’ll be able to have some
intermediate information at th at point, but probably not a final report. The pervious
pavement and detention will be next door.
What will you do to make sure the BMPs are maintained at the Grissum site? How often
will their effectiveness be monitored?
One of the things we’ll start look ing at is how well does the planting take hold? How
effective are those over time? Planting is a huge part of the bioretention and step pools,
we need to find out if as the roots increase, are they becoming more effective? How ewll
is the planting medium working?
The next thing that it goes through is the filtering media, which can get clogged. If you
put sand or anyutng like that, does it just get clogged with pollutants and bacteria. On the
step pool conveyance, what’s our cost to get that done? Are they pretty stable? Do we
have to move some o fthe rocks or vegetation to make sure it’s stable?
What data, specifically, do you hope to obtain as a result of the Sunrise Estates project
that won’t be available as a result of the Grissum BMP installations?
A couple things going on out there. There’s about 400 homes. Right now they get a lot of
problems with stormatwaer runoff. There’s no curbs and gutters. Creates ditches and
huge ravines in their front and back yeards. 100 acres, which is great for a test site. Plant
some additional trees. Kin dof a ‘softer approach’. How well the community likes these
products, how well they maintain them, and how they work over time. Looking at the
flow and the stage, we get 2 ½ inches of rain, how much does that
Rainfall event at this time of year, when there are no leaves on the trees and grass is cut
short. We can’t win them all, but we’re trying the best we can.
I assume this project has been approved by the homeowner’s association out there (east
of Columbia) or some similar organization?
Because this is, we have to use, because we’re getting federal funds, we have to match
that with local contributions. I knew a year and a half ago that we were going to be doing
street proejcts out at Sunrise Estates. I’m using the stormwater. Once we went out to the
homeowner’s associations, they were extremely ecstatic.
How closely have you been working with the city public works department? How
important will continued communication between the departments be moving forward?
It’s definitely huge. We’ve got a whole team over there that are fantastic. Erin Keyes is
the stormwater engineers.
How important will this public education phase be following the collection of data? What
do you expect that campaign to look like, ideally?
He more people that know the better. We will be targeting public works, power an dlight
guys. We’ll also be taking the information that we take from the samplers to the
engineers, private engineers that work in storm water. We’ll also be putting this info on
an international bmp database (google: international bmp) . We want to get Missouri
related information on that website. We’ll be reporting to city. Get a whole bunch of
different target audiences and lots of information