Recent articles on P removal structures or PSMs

Some articles are more recent than others.  Click to link.

Bell et al., 2014
Karczmarcyk and Bus, 2014
Klimeski et al., 2012
Klimeski et al., 2014
Lyngsie et al., 2014
Uusitalo et al., 2012
Canga et al., 2014
Lyngsie et al., 2014b
Penn et al., 2014
Wendling et al., 2014

New P removal structure leaflet

The field day presentation of the P removal structure in Westville, OK was successful.  This leaflet, which is an OSU extension document, was made available to those who attended.

The Structure is still removing a cumulative P load of at least 70%.  Thus far it has handled all flow, including an event that produced 500 gpm.

Depending on how quickly things proceed, the software for design guidance will be completed by the end of August and adoption into the EQIP cost share program should follow.

Spring update on P removal structure and presentation

Since installation in the fall, the P removal structure is still currently removing >90% of the cumulative dissolved P that has flowed into it.  Please see the following link for a recent presentation: http://dasnr.adobeconnect.com/p7kmw6j1uwt/

New published paper on structure design

This paper is open access at the Journal of soil and water conservation.  It summarizes much of the information in this blog regarding how to design a P removal structure tailored to a specific site.

We will continue to update this blog with results from the P removal structure.

First field day presentation of poultry farm structure and update

Field day announcement

There will be a field day presentation of the poultry farm runoff P filter on May 23rd, 2014 in Westville, OK.  The flyer and schedule of events is shown here.  Hope to see you there!  Please contact me for any additional information or questions.

Current performance of the structure

Since completion of the P removal structure last fall there has been very little precipitation here.  Thus far there has been only two events that have produced runoff at the site.  Both sets of samples showed nearly 100% P removal.  Due to problems with our connectivity to the automatic samplers, we cannot state what the flow rates were.  However, we will manually download the data to determine flow rates and duration.  

Installation and sieving of steel slag

Before pouring slag into the structure, it was necessary to sieve the material to > ¼”.  This was done on a large scale at a gravel quarry next door to the steel mill located in Ft. Smith, Arkansas.  A liner was placed on the bottom of the structure before dumping the sieved material into it.  A liner was also placed on the outflow side of the structure (i.e. “apron”) in order to channel all of the treated water into the flume for monitoring purposes. 

The sides of this outflow apron were constructed with railroad ties.  In the above picture they are covered with the liner.

The perforated drainage pipes were placed at the floor of the structure (on top of the liner) before covering it with the sieved slag.  Note that these drainage pipes channel water to the outlet of the structure, which is comprised of expanded metal.  Between 35 and 40 tons of slag was dumped into the structure use a skid steer:

 After the drainage pipes were covered with slag and the structure was nearly filled up, we installed the inflow manifold pipes.   These perforated pipes located just barely below the surface serve to evenly distribute runoff water throughout the surface of the structure:

We ran out of sieved slag near the end, so we had to sieve around 10 tons of slag to produce 6 more tons of >1/4” slag.  I’m pretty irritated in the picture below because the concrete vibrator that was used to screen the material kept breaking all of our U-bolts:

Eventually we ran out of U-bolts and we cleaned out the local hardware store for U-bolts.  At that point we had to sieve it the old fashioned way.  The guy on the right is Stan Roberts, a salesman from Automatic Engineering, the distributor for ISCO auto samplers in Oklahoma.  Stan was supposed to stop by to help with programming…..hahaha, but we put him to good use since we were not yet ready for programming.  That is a good salesman right there.  Steps out of the office and does some “hands on” work with no complaints. 

During the installation, we forgot to stabilize the downstream “gate”.  After it was filled with slag, the metal started to bow.  Note that the wood in the picture below was temporary.  It was removed after the slag was treated in-situ.

We managed to remove the bow in the metal gate using a come-along and 40 feet of chain.  After we pulled it back, we stabilized it by pounding several ½” rebar into metal sleeves welded to the gate.  I wish I had a picture of that process because it was pretty awesome.  Again, the slag was treated in-situ.  The samplers were set up (which is what we called Stan for!) and were placed in their own respective buildings:

We rolled out some erosion control mats and seeded uphill of the structure.  Trimmed the excess liner.  We also built a new suction head for the samplers to be able to handle a very shallow depth of water.

At this point we are ready to collect samples!  Just offhand, I hope that we can have a field day presentation in January.  We will continue to update this blog with results.

Preparing the Structure for Slag and Monitoring

The ISCO automatic samplers have finally arrived along with the flow monitoring equipment.   The flow and sample monitoring will be observed remotely at our office in Stillwater through the purchasing of a Verizon data plan.  Basically, we will be able to monitor what the samplers are doing/measuring at any time.  This way, when there is a flow event, we will know it immediately and obviously know to go to the site to collect the sample bottles as soon as possible for laboratory analysis. 

We recently poured some concrete at the inflow side of the structure.  The picture below shows the “before” picture and you can see that the inflow pipes (black) are at varying elevation from the surface, which is bare soil.  We wanted to create a clean and level “apron” where the inflow runoff water can enter the structure.  Eventually, there will be perforated plastic pipe attached to the other side (inside the structure) of the black metal pipe.  This pipe will be buried in the slag and will serve to evenly distribute the inflowing water (i.e. serve as a manifold).  

The next pictures show the concrete work:

 The finished product:

Also on this site visit we can to lay the pipe which will hold the suction lines for the automatic samplers and the bubbler tube for the flow monitor.

Not very exciting.  However next week we will sieve the slag and put it in the structure and finish up the installation of the monitoring equipment.

I would like to briefly highlight the work by Dr. Stefan Jansen in The Netherlands, here.