Mystery-of-the-Month - January

By Dave Vlasin

Erosion control measures are necessary even in underground tunnels.







 
What's been happening thirty feet underground this winter?


If you recall, last April we updated you on our Beltline Maintenance and Repair Project. We told you how District and Barr Engineering staff walked and inspected over 38,000 feet of the Beltline and Battle Creek Storm Water Tunnels. To read last year's article, click here.

 


Barr and District staff gathered information and took notes during the 2014-2015 Beltline inspection.



After the initial inspection, Barr employees used what’s called NASSCO (Nation Association of Sewer Service Companies) to put a severity grade on each defect, ranging from 1-5, with 5 being the most severe. These “grades” were averaged over a segment of tunnel which then gave us a better idea of areas that may need more attention. This resulted in roughly 10,000 linear feet of tunnel that RWMWD needs to repair.

Avoiding a waterfall in the tunnel.

After a bidding process, PCi Roads, LLC won the contract. PCi has two years to complete the project and were eager to get started on January 1st. They will continue to work all winter, as long as the cold weather allows. Next winter they will finish any remaining work. 


This type of work is best done in the winter months since everything is frozen and the risk of getting flooded out of the storm water tunnel is greatly reduced. 


PCi has currently prepped about 500 feet and are getting ready to begin filling cracks and complete surface repairs. 




To help you get an idea of what it's actually like to be making repairs in the tunnel, here are some pictures of work that's currently being done thirty feet underground.

PCi prepping the Beaver Lake Branch in January of 2017.



PCi employees working on the Beaver Lake Branch.



PCi cleaning and injecting material into cracks in the tunnel.

Before the spring rains kick us out, we hope to get at least a couple thousand feet completed. 

Mystery of the Month - May 2016

Here we have a concept model for the proposed remake of “Close Encounters of the Third Kind”. Or maybe it’s a piece of 1930s art glass. Perhaps a decorative fountain head for a water feature?


If I was unable to convince you with any of those suggestions, you are an astute (and skeptical) observer. What we really are presenting is the head of one of our showy aquatic flowers, the yellow pond-lily.

Nuphar seeds.

This common water plant has a good number of aliases. Common names for our featured flower include yellow waterlily, bullhead pond lily, cow lily and spatterdock. And with this plant, even the scientific name is up for debate, with many sources calling this species Nuphar variegata, and others insisting on the more cumbersome Nuphar lutea spp. variegata. Yellow pond-lily is a rooted aquatic plant, capable of growing in water up to 7 or 8 feet deep but more often found in much shallower water.



Yellow pond-lily is closely related to white waterlily (Nymphea odorata) and shares some of the characteristics that make them beloved and despised. Both are showy, attractive plants but also are capable of forming dense colonies, especially in nutrient-rich waters, that pose a significant impediment to watercraft. Yellow water lily is important to many wildlife species. Nuphar leaves and shoots are grazed by deer and other herbivores, they provide habitat for fish spawning, and the seeds are a food source for ducks and other waterfowl. Look for blooms in mid-summer to early fall.

Mystery of the Month: Where did Dave and Eric Go?

By Sage Passi

Could these be clues to Dave and Eric's disappearance?

When our Water Quality Team, Dave and Eric, recently disappeared from the office for ten days, I knew they were up to something. I didn’t think this current disappearing act was because they were inching their way through the seven miles of underground pipe in the Beltline Storm Interceptor from the Mississippi River to Lake Phalen again like they did last winter. (To learn more about that adventure, read “Fifteen Days Underground”.)

I knew something was up and wondered what could it be this time? I was determined to get to the bottom of their latest disappearance.

A little investigation and a phone call to Dave led me to an answer.

It was alum pond cleaning time.

Dave and Eric were on a mission for Tanners Lake.

That raised even more questions for me. How do you actually clean a pond? Why would you even think of cleaning a pond?

So, after learning their whereabouts from Dave, I drove cautiously to the unobtrusive building which had been Eric and Dave's "hideout" for the past ten days. I wondered what I would find there.

Dave and Eric's "Hideout" - the Alum Treatment Facility

I noticed there was a small barbeque grill sitting by the door and was glad to know they were still getting nourishment. Despite their remote location, and given Eric’s gourmet talents, my hunch was they were probably eating better than the rest of us back at the office.

The alum treatment facility has a big job protecting the water going to Tanners Lake. The lake is primarily used for recreation including swimming, skiing, boating, fishing, canoeing and picnicking. It discharges into Battle Creek Lake in Woodbury, which serves as the headwaters for Battle Creek, a tributary of the Mississippi River. 

The swimming beach at Tanners Lake in Oakdale

Protecting this lake only makes sense.

In 1997, the District set water quality goals for Tanners Lake to support swimming and other recreational uses. Since then, the RWMWD completed several capital improvement projects (CIPs) which contributed to significant improvements in water quality. These improvements have resulted in Tanners Lake being removed from the Minnesota Pollution Control Agency (MPCA) Impaired Waters List for excess nutrients (phosphorus).


Phosphorus levels have been reduced dramatically in Tanners Lake since the District began implementing a series of water quality improvements including the Alum Treatment Facility. Note: The yellow line indicates when the Alum Plant was installed in 1998. The data gap around 2010 was due to a change in labs when data was not collected.

One of the District’s water quality projects was the construction of a set of permeable weirs in a wetland north of the lake to slow the water down as it moves through the area so the sediments have more time to settle before they enter into the lake.

Another project was the creation of the alum treatment facility which treats stormwater from roughly 1,246 acres of land within the Tanners Lake Subwatershed. The Tanners Lake Subwatershed encompasses 1,732 acres, primarily in the city of Oakdale, with a small portion within the cities of Landfall, Woodbury and Maplewood. Tanners Lake, located near I-94 and Century Avenue, is a DNR protected lake.


The alum treatment facility treats over 70% of the Tanners Lake Subwatershed.

RWMWD began operating the alum treatment facility in 1998. The process of adding aluminum sulfate, otherwise known as alum, to stormwater is called alum injection. Once the alum gets into the water it binds the available phosphorus which creates the floc. This causes the fine particles to coalesce, clump (or flocculate) into larger particles. Alum injection can help meet downstream pollutant concentration loads by reducing concentrations of fine particles and soluble phosphorus. 

Alum treatment systems generally consist of three parts, a flow-weighted dosing system that fits inside a storm sewer manhole, remotely located storage tanks that provide alum to the doser, and a downstream pond that allows the alum, pollutants and sediments to settle out. 

When alum is injected into stormwater, it forms floc, which become heavy and precipitates out. These precipitates combine with heavy metals and phosphorus and sink into the sediment in a stable, inactive state. The collected mass of alum precipitates, pollutants and sediments is commonly referred to as floc.      

The building at Tanners Lake Alum Treatment Pond was constructed to house the alum injection equipment. The settling pond was created to retain the floc. This gives the alum time to react with the phosphorus. Once the majority of the phosphorus is removed, the water leaves the alum pond through a weir, and then is directed through a pipe that runs under Century Avenue. From there it is routed to a small wetland complex in Horseshoe Park in Oakdale and then enters Tanner’s Lake. This successful project currently removes 70 percent of all phosphorus entering the facility in a typical hydrologic year.



The Alum Treatment Pond

What did Eric and Dave actually do at the facility between 4 AM and 6 PM or later?

Shortly after my arrival, Eric Korte, the District’s Water Quality Monitoring Coordinator, drove up and climbed down to the pond to begin his tasks in this around-the-clock operation.

I took a step toward the mucky perimeter of the pond and decided not to go any further. The slope was slippery and I wasn't wearing my waders.

Eric unchains the boat at the edge of the pond, climbs in and starts the motor.




Eric stirs the floc with the boat motor.

E
Eric’s job for four to seven hours each day during this ten-day operation was to drive the boat around the pond stirring up the floc to suspend it in the water. Why? Over time the floc in the pond builds up and needs to be cleaned out. For the fall cleanout, the Watershed District was granted a permit from Metropolitan Council Environmental Services to pump the alum floc out of the pond into a nearby sanitary sewer.

I watched as Eric gunned the outboard motor repeatedly as he moved back and forth across the pond.

The District's Water Quality Technician, Dave Vlasin, was standing nearby watching Eric and commented,

“Eric’s method for mixing the water in the pond with the boat really worked well to re-suspend the floc. Within minutes after Eric stopped mixing with the boat we saw the floc settling out and the clear water emerging on the water surface. We were tuned into hearing the thickness of the floc as he passed.”

Floats attached to the GridBee AP4000 Air-Powered Mixer keep it from sinking to the
bottom of the pond. The mixer re-suspends floc in the alum pond.

In the middle of the pond I saw three huge bobber-like contraptions bouncing on the surface. I asked Dave what was their purpose and what was going on below the surface of the water.

“Eric and I installed a GridBee AP4000 air-powered mixer, which is an underwater bubbler in the alum pond to help re-suspend the floc in the water column to help it be more “pumpable.”

 

Diagram of AP4000 setup

To get an idea what the AP4000 set up looks like see diagram above. Picture a 55-gallon drum sitting on a plate with air diffusers on the bottom and then an air hose attached to the plate that helps circulate the floc.

Once the blower pumps are turned on; bubbles are forced up the drum, which creates suction at the base of that drum that draws in the surrounding floc. The pumped air forces the floc out the top of the barrel and the cycle continues. The longer the AP4000 stays on, the better job it does of suspending the floc and the larger the plume of floc that can be pumped into the sanitary sewer system.


Why did Dave and Eric decide to modify and take over the clean-out operation?

Dave commented,

“We had the opportunity to re-purpose a couple existing pumps that were no longer in use at the PCU Pond. That got us to thinking about improvements and ways to reduce the cost of cleaning out the floc at our Alum Pond. It’s expensive and has to be done every three to five years. We thought we could make some changes and save money for the district. It was costing about $30,000 each time it was cleaned up so we decided to try it ourselves,” said Dave.

“With our improved process, some additional equipment during this first year and doing it ourselves rather than hiring a contractor, we were still able to save about $10,000 including staff time. This savings will continue to grow because we will be depreciating the expenses we have incurred over time.”

I asked Dave if he ever got bored during this operation?

His answer:

“No. You are always doing something, even if you are waiting to do your next reading. There’s always something to else to do or pay attention to."

What tasks are involved in the alum pond clean-up?

“We have to collect grab samples that are representative of that day’s discharge. Each series of four grab samples are composited into one daily sample that is analyzed back in a lab for pH, chemical oxygen demand, total suspended solids (TSS), total phosphorous, nitrates, chlorides, mercury and a series of metals. The samples are picked up daily at the site by the Met Council."

Water samples drawn from the Alum Treatment Pond illustrate the amount of floc being collected in a day. Left to right, the percentage of alum increased as the day progressed.

"
"We also collect our own samples that we send to a lab for analysis. One of those samples collected each week is analyzed for PAH’s (polycyclic aromatic hydrocarbons) diesel range organics/gasoline range organics.”

He continued,

“We monitor the pH of the water. We keep track of the amount of water being pumped into the sanitary system by using a flow meter which displays the number of gallons of water pumped and its rate of flow." 
 


Dave takes a reading of the amount of sludge
water being redirected to the sanitary sewer.

During the clean-out Dave took regular readings of the number of gallons of sludge water being redirected to the sanitary sewer system during the permit period.

"We had a permit to discharge 1,200,000 gallons during our permit period so we had to monitor this carefully to stay within our discharge limit. We also had to make sure our pumps were operating properly and didn't get clogged.”

Dave unlocks, lifts the lid on a silver box in the ground and
uses a measuring stick to determine the depth of the pond.



During the cleaning operation, Dave said the level
dropped from 12 feet to about 3 feet of standing water.

During normal operations at the alum treatment plant, there is a direct relationship between the water flow through the system and alum dosage/treatment. This is all done by pre-programmed computers based on the numbers Dave and Eric enter.

As water flow increases from storm events, the dosage of alum also increases. The storm pipe can only handle a maximum of 5 cubic feet per second so anything beyond that bypasses the alum treatment process and goes directly into the nearby wetland system and then on to Tanners Lake. 

Dave and Eric’s normal water quality duties require them to monitor the operations at this plant including alum dosage, water flow and rates, pH levels and other perimeters.

Dave by the alum storage chamber

I asked Dave to show me around the rest of the site to see the other parts of the cleaning operation. 

We then headed to another locked box. This one Dave actually climbed into and down into the darkness below. 

The dosing/mixing chamber where the alum is dosed into the water

When Dave climbed out of that chamber we left the area and crossed the road to the other side where Eric was busy collecting a water sample.  

Eric collects a water sample to send to the lab.

I said goodbye to Eric and Dave after thanking them for helping me to understand how the alum treatment plant works.

Another mystery solved!

Feeling satisfied that I now knew where Dave and Eric had gone, I decided to head downstream to explore how stormwater makes it way to Tanners Lake after it leaves the alum treatment facility. Along the way, I discover a few other tricks the watershed district has up its sleeve to protect Tanners Lake.

I drove, following the pathway of the water. This is what I discovered.

My drive took me to Horseshoe Park.

At Horseshoe Park I saw water meandering through the wetland.

Following the backwaters, I discovered a permeable weir that
slows water traveling through the wetland. allowing it to be
filtered before emptying into Tanners Lake.

 

 

Periodically the District goes into Horseshoe Park and clears out
sediment that accumulates as stormwater passes through this wetland.

 

The water travels through this storm outlet
on its way to Tanners Lake, having been
cleaned upstream by the alum treatment.

  



The wetland complex in Horseshoe Park helps treat the
stormwater before it enters Tanners Lake.

 

 

The final destination of the stormwater from upstream is Tanners Lake.

 

Mystery of the Month - August

 

Think about the last thing you ate today. It’s been said that about 30% or one in three bites we eat are influenced by the behavior of bees. One in three! Not only that, the cotton in our clothes relies greatly on pollination by insects. (Check out other crop plants pollinated by bees here)


Unfortunately, due to the increased use of pesticides in agriculture and residential areas, those bee communities we rely on for food and cotton are disappearing. Changes in land use and popular yard choices (aka, turf grass) have also reduced the population by eliminating the habitat bees rely on for pollen and nectar, shelter, and resources to produce the next generation.


One in three bites!

 
What would our day look like if there were no bees left?

Bees are incredibly important. I personally rely on food and clothing a LOT so I certainly want to keep these tiny work horses around for their own good, and the good of an intricate ecosystem they hold in balance. Heck, maybe it is even time I started working for my kiwi and denim by undoing some of the damage we’ve done to a pollinator community these crops rely on.

Who are these bees? What plants do they frequent in my yard and in my local park? How can I help monitor their populations to know if a species is going under, remaining steady, or coming back?

Bee sure the Maplewood Nature Center has a way to get you the answers to these questions!


Bee-come a Bee Monitor! 

Join Maplewood Nature Center for an exceptional Citizen Science Pollinator Training and Survey at Maplewood Nature Center and Fish Creek Natural Area. (Adult program)

Date and Time: Saturday and Sunday, Sept 12 and 13 (Rain date is Saturday and Sunday, Sept 26 and 27)  Details for these two programs are as follows: 

Pollinator Training: Saturday, Sept 12, 10 am - 4 pm, at Maplewood Nature Center, Location 2659 E 7th St.
Bees are one of our most important pollinators, but little is known about the bees that live in our natural landscapes. Learn how to distinguish bees from other flower-visiting insects, how to identify honey bees and native bees, and methods for monitoring bees. Participants will gain practical experience with hands-on activities including working with pinned specimens, examining bees in a restored prairie, and practicing the methods for standardized data collection. The training is free and participants will receive a Citizen Scientist Pollinator Monitoring Guide and other reference material. Activities will include classroom and outdoor time. Wear comfortable walking shoes, long pants and long sleeves. Bring a hat, sunglasses, lunch and water bottle.

Bee Monitoring at Fish Creek: Sunday, Sept 13, 1-4 pm at Fish Creek Natural Area, Park on Henry Lane, Just off of Carver Avenue in South Maplewood.
Put your training to use to monitor pollinators at the new Fish Creek Natural Area. Participants will meet at Fish Creek to walk transects; survey for pollinators and learn about the Fish Creek restoration. Data gathered will provide baseline information that will be tracked as the prairie restoration matures. Participants need to be able to withstand tall grasses, uneven terrain. Wear Sturdy walking shoes.  

Both programs are free! Register by Sept 9. To register online, go to www.maplewoodnaturecenter.com or call 651-249-2170.

This course will be taught by Xerces Society Entomologists, Great River Greening Ecologists and City of Maplewood Naturalists. Funding for this project is provided by the Minnesota Environment and Natural Resources Trust Fund.




 

Mystery of the Month: Catch-Me-if-You-Can Grass

Phragmites —Native or Not?

 

By Carole Gernes

What sly, new, invasive grass mimics its closest relative so well that it can slip under our radar until its take-over is well underway?

The chameleon is the non-native invasive common reed grass; Phragmites australis australis; a European subspecies of a common reed that has become invasive in the United States.

Historically, it has been traced to an East Coast shipping yard, where it was thought to have entered the U.S. as ballast. It is a perennial, up to 15 feet tall, with large golden or purplish flowering heads in the fall. 

These plants spread via a thick underground stem (rhizome) network, resulting in a dense monoculture that is difficult to walk through. As the infestation grows, it excludes and replaces beneficial native plants. This grass has overtaken large portions of Great Lakes shoreline.

Phragmites rhizome

Part of the problem with this plant is the difficulty in differentiating it from the native, North American, common reed, Phragmites australis americana. Clues to identification vary with the season. 
In late winter and early spring, check to see if the plants have leaves attached to the stems and large, intact, thick fluffy, golden brown, seed heads. If so, the grass is likely the invasive subspecies.



 Early spring invasive common reed (Phragmites australis ssp. australis)

Photo credit Ken Graeve; MNDOT

If flower heads are few, thin, ragged-looking and leaves have fallen off from winter weather, it is likely a native plant.

Early spring native common reed (Phragmites australis ssp. americanus)

Photo credit Ken Graeve; MNDOT

 

In summer, look at the color of the plants. The invasive plant has bluish tinged leaves. The native plant leaf is more yellow-green. On close inspection, the native plant will have green stems throughout, with areas on the stem (nodes) that area a reddish-maroon color. If you rub your fingers along the stem of the invasive plant, it will feel slightly rough and look dull. The native plant’s stem will feel smooth and look shiny.

 Invasive common reed                                                                     Native common reed
Photo credits Ken Graeve, MNDOT

 

Once plants begin to flower, you may notice differences in the size and color of the flowering heads. The invasive variety has larger, fuller looking tops, which may have a golden or purplish color. The native plants have smaller, thinner, golden-colored flowers.

Invasive Phragmites australis                                                           Native Phragmites americana
Photo credits Ken Graeve, MNDOT

Because this past winter saw less snow than usual, some stands of common reed have been difficult to identify. The most definitive characteristics require measuring flower parts and other small parts.

Phragmites species begin to bloom in late summer to fall. Isolated patches do not set seed; they spread by rhizome. Size of infestations increase quickly in areas where additional, genetically diverse, patches are introduced, starting seed production. Seeds are set very late - in late October to early November. Once viable seeds are set, they jump-start spread of the plant.

Great Lakes Phragmites Collaborative is a good resource for more information about invasive phragmites. Download a PDF version of the Phragmite Field Guide to help you distinguish between native and exotic forms of common reed.

How can you help?

If you find a suspected infestation, contact coordinator Carole Gernes at 651-792-7977 or carole.gernes@rwmwd.org.
 

Volunteer! Free trainings for the Invasive Plant Patrol citizen science program will be held in March and April.

• Saturday, March 28 - Shoreview Community Center  To register, contact Carole Gernes at 651-792-7977 or carole.gernes@rwmwd.org.
• Saturday, April 11 - Maplewood Nature Center  To register, call 651-249-2170 or online at www.maplewoodnature.com.
• Saturday, April 25 - Tamarack Nature Center  To register, call Melanie Harding at 651-407-5350 extension 119. 

Note:  All class times are 10 am – 2 pm, with a 30-minute lunch break. 

Mystery of the Month - February 2015

Winter: Humans Survive & Bugs Do Too

"Monarch-butterflies-pacific-grove" by Agunther - Own work. Licensed
under CC BY 3.0 via Wikimedia Commons -
Link to image HERE.

By Zola Pineles

Winter is coming. Winter is…here! For humans, heat and comfort in the cold months can be relatively easy to procure thanks to amenities such as shelter, warm layers, our wits, and central heating. For insects, the winter means employing a number of different strategies to ensure survival.

Depending on the insect, diapause, freeze tolerance/avoidance, migration, and life cycle variations are methods that keep bugs crucial to Minnesota’s ecosystem alive for another season.

Diapause

Diapause is a state of suspended metabolic activity brought upon by external stimuli. In other words, when the days begin to shorten, and before the temperatures drop severely, insects increase their resistance to environmental extremes by storing additional energy reserves for the long winter. Similar to higher animals that undergo hibernation, insects will find space underground, beneath debris, in galls (bulbous outgrowth on some plant tissue), or in cocoons.

While in their respective shelters, insects dramatically reduce their activity to prolong their stored energy. For some insects, diapause occurs only if certain environmental factors cause a hormone in the brain to halt production and temporarily pause at the embryonic, larval, pupal, or adult stages of life.

When environmental conditions once again become favorable, the same hormone production picks up and the insect goes on its merry way to the next life stage.

 

Here are examples of some insects that undergo diapause: 

• Southwestern Corn Borer (late larval diapause)
• Silkworm (embryonic diapause)
• Gypsy month (late embryonic diapause)

Freeze Tolerance

Have you ever seen a science fiction movie where a character will cryogenically freeze or preserve themselves in low temperatures to be defrosted in exactly the same state years into the future? That’s kind of what some insects do to survive the winter temperatures.

 

Many species of insects have developed a tolerance to ice crystallization within the cells of the body to allow preservation through the cold winter months. Cryoprotectants, primarily glycerol, are small molecules within the fluids of the insects’ body that bind together and drop the internal freezing point of the insect. Freeze tolerance varies widely and can allow species such as the Alaskan beetle to survive at temperatures as low as -124°F.

Here are examples of some insects that are freeze tolerant.

• Wooly bear
• Flightless midge
• Alpine cockroach
• queen bumblebees



 Freeze Avoidance

"GoldenrodGallFlyLarva" by SriMesh - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:GoldenrodGallFlyLarva.jpg#mediaviewer/File:GoldenrodGallFlyLarva.jpg

While some insects embrace the cold and turn their bodies to ice, others avoid freezing at all costs. Supercooling is one method that some insect species use to prevent from freezing internally. Supercooling can only occur when the fluids within the insect are so pure that ice crystallization cannot occur – ice formation is dependent on the presence of a particle on which to attach – therefore the fluids do not turn to ice and injury is prevented during the cold winter months. This allows the bodies of some insects to remain unfrozen in temperatures as low as -76°F.

 

Here are examples of some insects that are freeze avoidant:

• Gall Moth
• Pine beetle
• Emerald Ash Borer
• Aphids
• Ticks

Migration

Monarch butterflies, like these flocking
to a blazing star bloom at our office in August,
migrate to warmer weather in the winter.

While some insects choose the hardy route and stick out the winter in subzero conditions, others choose to go someplace warmer. Migration is a technique that is used by a number of species, most notably monarch butterflies. During the summer months, adult monarchs mate and lay eggs which become the next generation. The last generation halts reproductive capabilities in order to make the southward journey. When October arrives, Monarchs east of the Rocky Mountains fly south to mountain highlands near Mexico City. Monarchs west of the Rocky Mountains fly south to Santa Barbara, California. When the cold winter months are over, the last generation of monarchs that flew down south makes the return journey north.

Here are examples of insects that migrate in the winter:

• Darner dragonfly
• Monarch butterfly
• Desert locust

In the End....

Though just a few overwintering techniques were listed, it is clear that insects have become highly evolved to withstand the same, if not worse conditions than we do. So next time you are feeling cold and you go to turn up the thermostat, think about the little things outside and be thankful.