Terms

• Water Reclamation Facility (WRF) – treats sanitary sewer wastewater on the western side of the SMSC reservation from enterprises and homes south of County Road 42.
• Biologically Aerated Filtration (BAF) – Large cement cells which hold the wastewater for treatment by a unique process utilizing Styrofoam beads laden with bacteria.
• Influent – Water and materials which flow into the Water Reclamation Facility from showers, drains, and toilets.
• Effluent – Clean water which flows out of the Water Reclamation Facility after treatment.
• Vegetative Green Roof - An extension of an existing roof which involves a special waterproof and root repellent membrane, a drainage system, filter cloth, a lightweight growing medium, and plants.

Construction

• This 30-month project was substantially completed in 15 months.
• It took about 140,000 man-hours to build using close to 100 workers.
• More than 6,000 cubic yards of concrete were used.
• 1.5 million pounds of reinforcing steel used.
• 68,000 (cinder) gray blocks in the interior and 64,000 brick on the exterior were each placed by hand.
• 1,130,000 pounds of limestone was used on the exterior.
• Principal designer was Bolton & Menk, Inc., Environmental Services Division, Mankato, Minnesota.
• Architect Plus of Faribault, Minnesota, designed the building.
• General contractor was Rice Lake Construction Group, Deerwood, Minnesota.
• In their contract Rice Lake Construction had a percentage goal of 20% Native American employees for the project, and they came in at 30%.

Biologically Aerated Filtration

• There are four BAF (Biologically Aerated Filtration) cells with a capacity for two future cells.
• Each BAF cell required about 1 full semi load of Styrofoam beads, which are to a depth of 10 1/2 to 11 feet in each cell.
• Each Styrofoam bead is 3.5 - 4 mm in diameter.
• Each of the BAF cells has approximately 1,400 nozzles.
• The BAFs are 13 feet 6 inches wide by 25 feet 2 1/2inches long.
• The BAF was made by Krueger, (also spelled Kruger) a provider of water and wastewater treatment process solutions, which is a subsidiary of Veolia Water, one of the largest full service water and wastewater companies in the world. Kruger AS was started in Copenhagen, Denmark, over 100 years ago.
• The BAFs are tall enough to run through all four stories of the building.
• The initial acclimation of filters took about eight weeks.
• Wastewater began flowing through the plant on August 9, 2006, to seed the filters, a process where the bacteria on the Styrofoam beads was allowed to grow. It’s that bacteria which “eats” suspended and dissolved solids in the wastewater.

Reverse Osmosis

• A reverse osmosis process was added to the front end of the water stream in 2009, allowing the discontinuation of water softeners.
• Reverse Osmosis separates the minerals and the water into two different “streams.” The smaller stream contains some water with all of the minerals. The other is mineral-free water. A portion of the minerals is then blended back into the water and the rest flows into the WRF as wastewater.

Air Scrubbers

• The air scrubbers move 13,600 cubic feet per minute of air through them.
• The two air scrubbers consist of a three stage air purifier and are 13 feet 9 inches long and 8 feet wide and 12 feet high.
• One air scrubber cleans air from pretreatment and one cleans air from the biosolids.
• Made by Siemens, aglobal powerhouse in electronics and electrical engineering, operating in the industry, energy and healthcare sectors.

Generator

• The generator is a 2005 Caterpillar diesel generator. It is a 1750 kilovolt-ampere, 1400 kilowatt 3 phase 480 volt generator.
• This unit has a States softswitch unit which monitors line utility and when there is any interruption it starts the generator and phases it in to run electricity to the plant.  When the line interruption has been stabilized for 30 minutes, it will switch back to line utility, cool down the generator, and shut it off automatically.

Ultra Filtration

• The ultra filtration unit is made by General Electric and is called a ZeeWeed 1000 unit. It provides a physical barrier against suspended particles, bacteria, viruses, and pathogens such as giardia and cryptosporidium. It removes turbidity, iron, manganese, organics, and color and THM (trihalomethane) precursors.
• This is a drinking water quality unit and cleans water by sucking water through a small micron opening in strands inside the filter. 
• There are thousands of these strands which look like spaghetti noodles in every module with 32 modules per filter at present.
• The SMSC WRF has four Ultra Filtration units.
• Two more ZeeWeed ultrafiltration units will be added in 2010 to keep capacity during cleaning (backwashing) of units for a total of six units. During cleaning will stil be able to have 4-5 online at a time.

Ultraviolet Filtration

• Treated effluent from the processed waste stream is directed through a number of ultraviolet (UV) channels, where it is exposed to UV radiation in a series of UV reactors or banks.
• Each bank is composed of a quantity of modules, each comprised of two columns of discharge tubes, or lamps, similar in appearance to fluorescent lighting tubes. 
• These lamps are housed in a quartz sleeve, which are placed in the UV channel, parallel to the direction of flow. 
• As the effluent passes over these lamps, microorganisms are exposed to UV light with a wavelength of approximately 254 nanometers.
• UV light is lethal to microorganisms. 
• The effectiveness of UV irradiation is due to its ability to cause rearrangements in the genetic material of microorganisms, preventing the microorganisms from reproducing effectively, inactivating or killing the microorganisms.

Discharge

• The plant is permitted to discharge approximately 1.5 million gallons of treated wastewater per day in its current configuration.
• Actual summer usage ranges up to 450,000 gallons per day.
• Winter usage ranges from 330-350,000 gallons per day.
• The WRF averaged about 350,000-375,000 gallons of influent per day for the first six months.
• The entire amount of effluent flows into the wetlands by Dakotah Meadows Mini Storage in the winter. -In the summer about 200 gallons a minute are pumped through the water feature into the wetlands adjoining the WRF.
• Effluent is also used directly from the WRF to irrigate landscaping.
• Temperature of the effluent is 63 degrees Fahrenheit.
• Minnows are flourishing in the wetlands where the effluent is discharged, a sign of the purity of the water.

Pilot Injection Study

• Pilot study of an underground discharge system using DSIR Methodology: Deep Subsurface Injection and Rechargebegan in May 2009.
• Researching possibility of injecting effluent into the groundwater to recharge the aquifer.
• At a quantity of one gallon per minute, the bench scale study looked at what level of pharmaceuticals and personal care products (shampoo, soap, etc.) were in the water and how it could be removed. On July 17, 2007, samples were taken and submitted for testing to the Unites States Geological Survey.
• An Advisory Group of staff from the Minnesota Pollution Control Agency, the Minnesota Department of Natural Resources, the Metropolitan Council, the SMSC, the City of Prior Lake, Shakopee, and Scott County met to discuss the project and devise an action plan.
• Capacity during study is 80-90 gallons a minute through a reverse osmosis unit to further treat water for injection.
• Focus is removing endocrine disrupters or hormonally active agents and pharmaceuticals.
• Promising results thus far.
• If this project ultimately goes forward and is successful in injecting reclaimed wastewater into the groundwater, it would be the first time this technology has been used in the United States.

Future Growth

• There is an option to expand the WRF by adding one more clarifier, two more BAF filters, and an additional ultraviolet disinfection unit.
• Future capacity will allow the discharge of up to 2.17 million gallons per day.

Biosolids

• The first run of the biosolids operation was December 12, 2006, which yielded 1,705 pounds of dried solids. A second run January 8-9, 2007, yielded 1,749 pounds. A third run yielded 1,699 pounds January 16-17, 2007.
• The WRF presses biosolids every other week for five days at a time.
• Drying time varies as to time containment in dryer depending on the consistency of the sludge.
• We have the capability of changing speed on the belts to regulate temperatures.
• It takes approximately 1.25 hours to dry biosolids.
• Moisture content ranges 94-96% dry.
• The biosolids dryer is supplied by Krueger but is called Bio con and is made by a European company.
• The biosolids presses are Ashbrook 2 meter presses.
• In 2009 119.179 dry tons or 108.12 metric tons of biosolids were produced.
• CEM Smart 5 moisture tests are conducted on product during runs.
• Reports on the biosolids are submitted to both the Minnesota Pollution Control Agency and the Environmental Protection Agency – Region 5.  These reports include tests for annual 503 regulated set of heavy metals, phosphorus, potassium, and nitrogen testing.  Fecal coliform testing on samples is done annually. If needed, such as if one of the runs goes under temperature, sample fecal coliform testing is done on that portion of the run.

Vegetative Green Roof

• The WRF contains a 30,200 square foot "Green Roof," the largest in the Midwest with seedlings planted and seeds planted.
• A seven-man planting crew from Aloha Landscaping of Mendota Heights hand planted the roof over a two-week period beginning July 24, 2006.
• Initial planting of 45,846 plugs: 28,164 sedum in 9 varieties and 17,682 native plants in 23 varieties.
• Six inches of light-weight soil, consisting of: 10% pine bark, 30% sand, 60% haydite.
• Planted during high temperatures and drought conditions.
• By third full growing seasons the green roof was thriving, plants growing, producing seeds and seedlings.
• Many wildlife are utilizing the vegetated roof habitat for food, shelter, and reproduction. 
• Pollinators found on the green roof: bumblebees, solitary bees, honeybees, hoverflies, wasps, butterflies, moths, and beetles. 
• Other fauna/wildlife found on the green roof: caterpillars, grasshoppers, orb spiders, jumping spiders, garden spiders, tree frogs, and ducks
• Most common weeds found on green roof: sow thistle, cottonwood seedlings (a tree), and cattails.
• About 50 different species of plants live on green roof.
• Native plants found on the green roof: Alumroot, beardless birdfoot violet, bellflower, blue grama, columbine, grey goldenrod, ground plum, junegrass, little bluestem, long-headed thimbleweed, partridge pea, pasqueflower, prairie dropseed, prairie smoke, purple prairie clover, rough blazing star, side-oats grama, silky aster, sun-loving sedge, western spiderwort, wild garlic, wild petunia, and wild prairie onion.
• Traditional green roof plants: 11 different stonecrops and wild chives.
• Volunteer plants (dropped by birds, carried by the wind, etc.): big bluestem, cattail, chickweed, cinquefoil, cottonwood, fame flower, fireweed, horseweed, lovegrass, mollugo, sowthistle, wild rye, willow, winged pigweed, and Venus looking glass.
• Green roof is irrigated with effluent.

Benefits of Green Roof

• Minimizes impervious surface area
• Storm water—absorbs, slows, and cleans about 580,000 gallons of storm water per year
• Moderates temperatures of roof runoff
• Lowers energy costs for heating and cooling
• Cooler when water is held on surface or in soil
• Plants absorb and transform solar radiation in biomass and latent heat thus preventing wild temperature swings
• Lowers heat loss due to wind
• Extends roof life
• Can outlast conventional roof by more than three times
• Designed for a 50 year lifecycle, as opposed to 12 years for a standard roof
• Improves urban air quality
• Leaf surfaces capture pollutants
• Plants convert carbon monoxide to carbon dioxide
• Decreases urban heat island effect
• Provides sound insulation (substrate blocks lower frequencies; plants block higher frequencies)

Awards

• The Minnesota American Council on Engineering Companies (ACEC) presented the SMSC with one of nine Grand Awards for the best overall engineering achievement.
• The Minnesota Society of Professional Engineers (MSPE) 2007 Seven Wonders of Engineering Award was presented to the SMSC February 23, 2007, in Bloomington, Minnesota.
• The SMSC facility was also awarded the Minnesota Governor’s Award for Excellence in Waste and Pollution Prevention February 28, 2007.
• In February 2010, the SMSC WRF was selected as a Semi-finalist for the Harvard Project on American Indian Economic Development Honoring Nations 2010 award.

Miscellaneous

• The SMSC has hosted more than 50 tours with hundreds of visitors to groups ranging from dignitaries to tribal planners to city workers.
• Water flowing out of the facility is cleaner than the wetlands into which it flows. It is as pure as water which comes directly from the groundwater.
• Total Building Floor Area = 53,200 square feet
• Total Building Roof Area = 38,100 square feet
• The WRF is administered by the Shakopee Mdewakanton Sioux Community Public Works Department.