the reactive stream stabilization (rs2) research

THE REACTIVE STREAM

STABILIZATION (RS2)

RESEARCHKnowledge by Dr. Chester Watson, Dr. David Biedenharn, & Dr. Ken Carlson. Drawings by

Dave Derrick

Presentation Presentation OverviewOverview

1. Environmental significance2. Objectives of project3. Reactive Stream Stabilization Structures

- Denitrification, Phosphorus Removal- Field study description and construction

4. Preliminary lab results5. Proposed full-size test site, Ellicott, MS

Problem: EutrophicationEutrophication

• The Gulf of Mexico

"Dead Zone", or hypoxic zone, covers 7,000 sq. miles at times during the summer

• Current estimates suggest that three times as much nitrogen is being carried into the Gulf today compared with levels 30 years ago

Figure and information from National Center for Appropriate Technology

Agricultural Agricultural HydrologyHydrology

• Erosion can destroy the riparian zone and lower the water table

• Compromised riparian zones result in an increase in sediment and nutrient transport

streamwater table

stream bank

Nitrogen (N)Nitrogen (N)For Mississippi River

watershed…[1]• Annual N losses in

surface runoff range from 1- 50 kg/ha, depending largely on the amount of sediment lost

• Annual N losses through leaching into subsurface drains ranges from 2- 130 kg/ha

Phosphorus (P)Phosphorus (P)• Manure and fertilizer are applied

based on crop N requirements – 2 to 3 times excess P

• Phosphate pollution is the major cause of algae blooms in many lake waters in the Mississippi Basin (limiting nutrient)

• Erosion is the major P transport mechanism – transport during surface runoff events

Objectives of ProjectObjectives of Project

Primary Objective = Minimize bank erosion

Secondary Benefit = Reduce N and P loads

Passive Reactive Barrier

Longitudinal Peaked Stone Toe Protection

(LPSTP)Field Demonstration Study:

Reactive stream stabilization (RS2) structure

RS2 Structure RS2 Structure

Anaerobic Reaction Anaerobic Reaction ZoneZone

Denitrification

NO3- N2 (g)

Carbon source (sawdust)

Saturated (anaerobic)

Phosphorus removalAlum based

water treatment residuals (WTR)

Ratio of…• sawdust (20 vol %)

• coarse sand (35%)

• silt sand (35%)

• native soil (10%)

Ratio of…• sawdust (19 vol %)

• coarse sand (33%)

• silt sand (33%)

• native soil (10%)

•WTR (5%)

Irrigation/ Fertilization

A: Denitrification

B: Control

C: Denit./P removal

CSU Lab test layout

Research Monitoring & Research Monitoring & AnalysisAnalysis

• Hydrolab used to measure DO, ORP, temp, conductivity, turbidity & pH

• Lab measurement of ortho-P, NO3-N, TOC, alkalinity and NH3-N

FIELD LAB EXPERIMENTS AT COLORADO STATE UNIVERSITY

Four field cells (one control), 3 reactive amendments

1) Organic matter (sawdust)DenitrificationBiodegradation of pesticides

2) Water treatment residual (Al)Adsorption of P

3) Zero valent iron (ZVI)Abiotic reduction of pesticides, nitrateBiodegradation of pesticides

0.04 0.05 0.09 0.04

99.499.4

99.2

99.5

0

2

4

6

8

10

12

NO

3-N

(m

g/L

)

98.6

98.7

98.8

98.9

99.0

99.1

99.2

99.3

99.4

99.5

99.6

% R

em

ov

ed

Feed 6.89 7.30 10.70 9.50

Effluent 0.04 0.05 0.09 0.04

% Removal 99.4 99.4 99.2 99.5

6/22/2005 9/12/2005 3/31/2006 7/14/2006

Colorado State Field LabColorado State Field Lab Nitrogen Removal Results

0

10

20

30

40

50

60

70

80

90

100

Cell A (sawdust) Cell B (control) Cell C (WTR)

Ave

rage

P R

emov

al (%

)Colorado State Field LabColorado State Field Lab

Phosphorus Removal Results

Organic amendment (sawdust) to a RS2 structure significantly enhances nitrate removal relative to soil-only.

Water treatment residual (WTR) amendments significantly reduces P release to a stream.

Commonly used pesticides can be removed with zero valent iron (ZVI) as an amendment although atrazine removal appears limited abiotically.

Additional research is focusing on the role of biodegradation with mature ZVI & WTR systems

Colorado State Field Lab - ConclusionsColorado State Field Lab - Conclusions

Sources CitedSources Cited• Downing, John A. 1999. Gulf of Mexico

Hypoxia: Land and Sea Interactions. Council for Agricultural Science and Technology (CAST), Ames, IA. 44 p.

• Pionke, H.B., Gburek, W.J., Sharpley, A.N., and Zollweg, J.A. 1997. Hydrologic and chemical controls on phosphorus losses from catchments. Phosphorus Loss to Water from Agriculture. C.A.B.I., Cambridge, p. 225-242.

Looking US @ entrance conditions into project bend.

PRE-PROJECT - RS2 PROJECT-LITTLE BOGUE PIX BY DAVE DERRICK 4-2-08

FULL-SIZED TEST SITE - CONSTRUCTED NOVEMBER19-20, 2008

LITTLE BOGUE, ELLIOTT, MS

Landowner is Cannon Kirk, phone 662-226-3632.

Location: Exit I-55 @ Elliott, go east on Camp McCain Rd.,

after 4-6 miles turn right (east) on Hayward Rd., it is

the first bend upstream of the first bridge.

Aerial view with approximate research project trench test location in yellow & control section (trench not dug) in pink.

PRE-PROJECT - RS2 PROJECT-LITTLE BOGUE FROM RED HEN VIDEO

RS2 CONSTRUCTION @ LITTLE BOGUE, ELLIOTT, MS.

Dig a trench approximately 1 ft wide, 4 feet deep & 150 feet long.

1) Mark alignment of trench2) Stage chemical and mulch along trench3) Using backhoe with 1 ft wide bucket, dig small section of trench & backfill with a mix of 20% Aluminum Sulfate (by volume), 20% Eucalyptus mulch (carbon by volume), & the remainder native material from trench.4) Move backhoe to next section and repeat dig/backfill procedure until half of the trench length (75 ft) has been constructed.5) Method is the same for the next 75 ft but adventitious rooting poles will be put in the trench , then the trench will be backfilled. Vegetated test plots of Willow, Sycamore, & River Birch will each be 25 ft long.6) Install monitoring wells up-gradient and down-gradient of trench to analyze nitrogen and phosphorous removal.

Trench was backfilled with materials to provide a reactive barrier to nitrogen (N) and phosphorus (P).

Organic matter (OM) was added as a carbon (C) sourcewhich is required to sustain the microbial denitrification reaction the removes N.

Alum (aluminum sulfate – Al2SO4) was added as a precursor to the formation of aluminum hydroxide (Al(OH)3), a precipitate that effectively and strongly adsorbs P from water.

Organic matter in the form of eucalyptus mulch was added within a target volume fraction range of 15-20% v/v. The type and range of OM has been optimized in the lab.

Alum was added to achieve a weight fraction of aluminum (Al) in the trench of 1.8-2.0% w/w. The Al weight fraction is the key design parameter for P removal and the range chosen has been studied extensively at bench and pilot scale.

THE PLANDrawings by Dave Derrick

Existing condition of floodplain landward of existing LPSTP –

flow is toward the viewer

Good native vegetation on floodplain bench & bank

RS2 Test Site: Little Bogue, Elliott, MS Corn field in 2007, Cotton field in 2008

RS2 Test Site: Little Bogue, Elliott, MS

On the narrow mid-bank bench (average width 8-10 ft, approx. 8 ft above the streamside floodplain bench), a trench a bucket wide (1.0 ft) was dug to

a depth of 4 ft. This should intercept a large percentage of shallow groundwater.


There is a 75 ft long control section (nothing done, no trench, just monitoring instruments), and a 150 ft long test trench section. Within the downstream 75 ft of the test trench, three 25 ft-long test plots of adventitious rooting poles of Black Willow, Sycamore, & River Birch were placed, spacing varied from 1 to 2 ft.


For the test section shovels were used to backfill the trench with a mix of 20.2% (by volume) Aluminum

Sulfate, 18.7% mulch, and the remainder native material from the trench. This also effectively

planted the live poles to a depth of 4 ft.


Monitoring instruments determine performance of the control and planted & not planted test sections. Instruments at different depths

will determine if some groundwater is bypassing the test trench.


According to the CSU laboratory tests, the Aluminum Sulfide and carbon (mulch)

should greatly reduce the Nitrogen & Phosphorus load to the stream.

Tall bank

RS2 Test Site: Little Bogue, Elliott, MS - aerial view

Little BogueExisting LPSTP

Floodplain bench formed by suspended sediment from the

stream that was deposited landward of the LPSTP.

Active rotating crop field - Cotton or Corn

Steep sloped bank

Small active gullies at edge of top bank were repaired during this effort


Footprint of RS2 test trench-150 ft

long

75 ft long

control section-

trench not dug

Flow

Small active gullies at edge of top bank were repaired during this effort


Within the downstream 75 ft of the test trench, three 25 ft-long test plots of

adventitious rooting poles of Black Willow, Sycamore, & River Birch were placed,

spacing varied from 1 to 2 ft.

Flow

Install instrumentation to monitor long-term project performance.

200 ft


PRE-PROJECT PHOTOSby

Dave Derrick April 2, 2008

Looking US @ the project bend, Little Bogue, Elliott, MS.


Flow

Looking US @ the project bend, Little Bogue, Elliott, MS. Existing Longitudinal Peaked Stone Toe Protection &, floodplain bench


Looking US @ entrance conditions into project bend. Note floodplain bench, & mid-bank bench where the test will occur.


Looking US @ the mid-bank bench where the test trench will be conducted. Control area in pink, test trench location in yellow.


Looking landward from the LPSTP. Arrows show bench where 4 ft deep test trench will be dug.


Top bank above test trench area. Cotton field to right, pine tree buffer between stream & cotton field


Looking DS @ trench location on mid-bank bench.


PRE-PROJECT PHOTOSby

Dave Derrick November 19, 2008

Looking DS @ pine tree buffer to left & test bench-floodplain bench area to right. Note lush growth.


Looking DS. Note lush growth on floodplain bench. Willow, River Birch, and Sycamore will be harvested from there.


Looking DS. Test trench will be on mid-bank bench.


Looking US. Test trench will be just US from Biedenharn


Harvesting cotton on top bank.


LET’S DO SOME

RESEARCH !!

1ft

4ft

Design concept of Reactive Stream Design concept of Reactive Stream Stabilization (RS2) on Little BogueStabilization (RS2) on Little Bogue

From Drs. Dave Biedenharn & Chester Watson

THE EQUIPMEN

T

The tracked mini excavator & Bobcat skid-steer with auger

CONSTRUCTION-RS2 PROJECT-LITTLE BOGUE PIX BY DAVE DERRICK 11-19-08

Bobcat skid steer delivering topsoil to repair gullies on top bank.


RS2 CONSTRUCTION @ LITTLE BOGUE, ELLIOTT, MS.

Construction resources required:1) Tracked mini-excavator (12” bucket) for 2 days2) Tracked skid steer with bucket and auger4) 4 laborers for 2 days (us)5) 3-50 bag pallets of Aluminum Sulfate6) 70 bags of Eucalyptus mulch7) Observation well equipment

Additional resources needed: knowledge

CONSTRUCTION PHOTOS

by Dave DerrickNovember 19-20, 2008

Two 50 bag pallets of Aluminum Sulfate.


Truckload of Eucalyptus mulch (1.5 cu. ft per bag).


Off loading & staging Aluminum Sulfate at test site.


Two bags of Aluminum Sulfate for each bag of Eucalyptus mulch


Looking US @ staged test materials


Looking US @ staged material on mid-bank bench.


Looking US @ excavator with 2 PhD’s shovel backfilling trench


From cab looking US. Mixing sulfate & carbon with backfill material


Hand labor is used to mix Aluminum Sulfate & mulch with backfill. Next time another excavator will be used to mix and backfill, we are

learning!! No plantings in this first 75 ft. of trench.


Looking US. Test plant Sycamore tree cuttings in trench.


Trench was dug to a consistent depth of 4 ft for entire length


John McCullah says,

“Dig a hole, plant a pole!!”

We did….

In background 25 ft of Sycamore poles planted in trench, foreground 25 ft of River Birch poles.


Planting and trenching complete. Excess soil will be smoothed, seeded, & mulched. A small berm will be built

streamward of the trench to slow rainfall & potentially some surface runoff will infiltrate into trench & undergo treatment.


Looking US @ trench with plantings, & small berm (potato ridge levee) streamward of trench


Looking US @ seeded & mulched trench, berm, & plantings.


Looking US @ adventitious rooting plants in trench


Looking US, close-up of pole plantings in trench


From top bank, looking DS @ completed test trench


Looking DS @ completed seeded & mulched test area.


Looking US @ control test area (undisturbed except for installation of monitoring instruments).


GULLY REPAIR ON TOP BANK

Landowner’s pine trees were all flagged so as to not be damaged during gully repair activities


One of several gullies on top bank that were repaired concurrently with construction of the test trench.


Repaired gully with small ring levee (potato ridge ring levee). Seeded with winter rye grass & mulched with hay


Dave & Chester mulching top bank gully repair areas.


Looking US. Project complete, backing equipment out.


MONITORING INSTRUMENT

INSTALLATION PHOTOS BY

CHESTER WATSON JANUARY 12, 2009

Dr. Biedenharn with some of the monitoring instruments.

MONITORING INSTRUMENT INSTALL-LITTLE BOGUE PIX BY WATSON 1-12-09

Looking US @ test site. Excellent planted grass coverage.


Looking US @ the test area. Great rye grass growth on all disturbed areas.


Water & soil samples Water & soil samples taken in May and July taken in May and July

2009.2009.

Monitoring wells Monitoring wells installed January 2009.installed January 2009.


7 MONTHS AFTER PROJECT

COMPLETIONPhotos by Derrick

JULY 3, 2009TAKING SOIL SAMPLES

Looking US @ test site. Excellent planted grass coverage.

7 MONTHS AFTER TRENCHING-LITTLE BOGUE PIX DERRICK 7-3-2009

Looking US @ the test site. All planted poles died except for one willow!!!


Close-up of the one willow that lived.


Looking downhill at one of the monitoring wells.


Ground water & soil sampling protocol from

Dr. Ken Carlson,

Colorado State University.

Tools used to take a soil sample 16 inches below the surface.


Very dry for the top 7 inches or so in each of the 15 soil sample holes


Soil Sample ResultsSoil Sample Results Total phosphorus reduced by about 44% through RS2. Increased by Total phosphorus reduced by about 44% through RS2. Increased by about 58% through control section. The bio-available phosphorusabout 58% through control section. The bio-available phosphorus

was decreased by about 55% through RS2, and by about 20% throughwas decreased by about 55% through RS2, and by about 20% throughcontrol sectioncontrol section


Well Sample ResultsWell Sample Results• Total nitrogen (TN) reduced by 40%

• Nitrate (NO3-) reduced by 51%

• Aqueous phase Total Phosphorus (TP) reduced by 31%

• Aqueous phase Dissolved Reactive Phosphorus (DRP) reduced by 14%

• Total Organic Carbon increased by 590% (most likely due to mulch amendment to barrier)


17 MONTHS AFTER PROJECT

COMPLETIONPhotos by Derrick

April 5, 2010

Looking US. Nature has taken over the test site


Several planted willows were growing & thriving. Most of the other plants probably died due to the poisonous to plants natural

chemical found in the eucalyptus bark mulch that was used.


SummarySummary The initial results from the Little Bogue

Reactive Stream Stabilization project are very encouraging. The design objectives of installing a reactive barrier with significantly elevated concentrations of aluminum for P adsorption and bio-available organic matter for enhanced nitrogen removal appear to have been achieved. Based on sampling data from 5 and 7 months after construction, the RS2 structure appears to be removing significant amounts of N and P from agricultural runoff that would normally enter the creek.


Questions?

Cleophus Speed Elvis Derrick at rest

Assuming the trench is 150x4x1 (Dave's PPT), the volume % of alum added was

20.2 and the organic matter was 18.7% vol/vol (75 bags of mulch, 1.5 cu ft/ bag). Since all of our pilot and demonstration data was based

on WTR, we should probably report the weight fraction of aluminum added rather than a volume fraction of alum. In this case,

alum has an Al weight fraction of 8.6% leading to an in-trench aluminum fraction of 1.7% by weight. This equates to a WTR v/v

fraction of 18%, reasonable since we were initially aiming at WTR fraction of 10-20%.


the reactive stream stabilization (rs2) research

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