Cost/benefit Analysis of Stormwater Pond Alternative Management Controls Demonstration Project Mark Clark Wetlands and Water Quality Extension Specialist Partnership for Water, Agricultural and Community Sustainability at Soil and Water Science Department
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Cost/benefit Analysis of Stormwater Pond Alternative Management Controls Demonstration Project
Cost/benefit Analysis of Stormwater Pond Alternative Management Controls Demonstration Project. Mark Clark Wetlands and Water Quality Extension Specialist Partnership for Water, Agricultural and Community Sustainability at Hastings Soil and Water Science Department. Acknowledgement. - PowerPoint PPT Presentation
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Cost/benefit Analysis of Stormwater Pond Alternative Management
Controls Demonstration Project
Mark Clark
Wetlands and Water Quality Extension SpecialistPartnership for Water, Agricultural and Community Sustainability at Hastings
Soil and Water Science Department
Acknowledgement
• Grand Haven CDD Board and Community • Dr. Stephen Davidson • Barry Kloptosky and Tom Lawrence • Aquatic Systems Inc. and Austin Outdoor • Jim Cook • Byron Kort • The many volunteers who assisted with data
collection and sampling, without their help and dedication, projects like this can’t happen.
Outline
• Review of treatments
• Monitoring methods
• Part I -Key findings for algae, water quality and aquatic life
• Part II - Key findings for fertilizer, reclaimed water, soils and sediments
• What next
Grand Haven CDD Symposium(January 22, 2008)
• “What ecologically sound and fiscally responsible measures can the governmental organizations, Hampton Golf, and all property owners/residents of Grand Haven take to:
1. Maintain the health of our storm water detention ponds (aka “lakes”)?
2. Correct and prevent recurring problems such as algae blooms?”
Alternative Lake TreatmentsAlternative Lake Treatments
Littoral Shelf PlantingLittoral Shelf PlantingAerationAeration Carp Control / SAVCarp Control / SAV Copper SulfateCopper Sulfate
Monitoring Methods• Monthly monitoring
– August 13,2009 -January 15, 2010
• Volunteer Observation– SAV cover (% floating, % submerged), – Water Clarity (scale 1-5)– Aquatic life assessment
* Per acre cost, does not include electricity** Unofficial quote
*** Does not include corrective treatments
Estimated Annual Maintenance Cost of Alternative Treatments
Treatment Alternative Summary(Copper Sulfate)
• Positive– Low cost, – fast acting, – one of two most effective at filamentous algae
control
• Negative – Increased nutrient levels in water column – Short-term effect with need for repeat treatments – Reduced water column clarity – Negative effects on aquatic life – Source of elevated copper levels in sediment
Treatment Alternative Summary(Aeration with Microbes)
• Positive – Increased abundance of aquatic life – Some improvement in water column total
phosphorous concentration
• Negative– Least effective treatment at filamentous algae
control– Most expensive treatment to implement
Treatment Alternative Summary(Littoral Shelf Planting)
• Positive– One of most effective treatments for floating filamentous
algae control – Highest water clarity and lowest color rating of treatments – Highest aquatic life abundance in some categories – Lowest water column nitrogen and phosphorus levels – Only treatment with total nitrogen to total phosphorous ratio
above 20• Negative
– Perceived benefits may rely heavily on SAV component of treatment
– As implemented in study this treatment is prone to invasion by exotics and nuisance species as well as aesthetic concerns
– Moderate cost of maintenance
Treatment Alternative Summary(Submerged Aquatic Vegetation)
• Positives (based on August 13, 2009 sampling)– Could significantly reduce total nitrogen and
phosphorus concentrations in water column– Could provide best water clarity – Could improve some aquatic life categories
• Negative– Treatment did not meet homeowner acceptability
standard in two out of three ponds being assessed
Part II
Sources of Nutrients to Grand Haven Stormwater Ponds: Fertilizers, Reclaimed
– Ponar dredge– Analysis for TP, TCu, Water extractable P
50%27%10%13%Grand Haven
29%14%29%29%G
60%40%0%0%F
100%0%0%0%E
40%20%40%0%D
57%29%0%14%C
57%29%14%0%B
11%56%0%33%A
Very HighHigh MediumVery LowCatchment
50%27%10%13%Grand Haven
29%14%29%29%G
60%40%0%0%F
100%0%0%0%E
40%20%40%0%D
57%29%0%14%C
57%29%14%0%B
11%56%0%33%A
Very HighHigh MediumVery LowCatchment
Soil Test Levels of Phosphorus in Grand Haven
0%
10%
20%
30%
40%
50%
60%
Very Low Medium High Very High
Phosphorus Test Level
% o
f so
ils t
este
d
Spatial heterogeneity
in soil phosphorus
concentration
77% of soils sampled – no phosphorus fertilizer recommended
Fill Soils Phosphorus Concentration
Fill SoilFill SoilNative SoilNative Soil
Fill Soil Phosphorus
Inputs
Upland Soil Mehlich-1 Extractable Phosphorus
( mean and range)
0.0
50.0
100.0
150.0
200.0
250.0
Native soil Fill soil Common area Turf Residential Turf
Sampling location
Ph
os
ph
oru
s c
on
ce
ntr
ati
on
, m
g/L
a
a
a
b
Upland Soil pH(mean and range)
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
Native soil Fill soil Common area Turf Residential Turf
Sample location
pH
aa a
b
5,450% 4% 20%
Common Area Fertilizer Inputs
• Application date Total amount and formulation– March 2009 71 bags (50 lbs. each) of 8-2-12 (N-P-K)– June 2009 71 bags (50 lbs. each) of 10-0-15 (N-P-K)– November 200957 bags (50 lbs. each) of 19-0-19 (N-P-K)
• This translates into – 1180.5 lbs of nitrogen– 71 lbs of phosphorus as phosphate (P2O5) or – 31.24 lbs as elemental phosphorus.
– Upper end UF/IFAS recommended rate for nitrogen • 2-5 lbs. N/1000 sq ft / yr
Average Rainfall 48.9 in Estimated irrigation need 20-35 in
Sediment Phosphorus Concentration
Sediment Phosphorus Concentration
(Mean and Range)
0
2000
4000
6000
8000
10000
12000
5 8 18a 2 19 20 6 7 17 1 3 4 28 W6
Pond Number
Ph
osp
ho
rou
s C
on
cen
trat
ion
, m
g/k
g
Sediment Phosphorous Inputs
Water Extractable Phosphorus Concentration (Mean and Range)
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
5 8 18a 2 19 20 6 7 17 1 3 4 28 W6
Pond Number
Ph
osp
ho
rou
s C
on
cen
trat
ion
, mg
/kg
Sediment Copper
Concentration
Sediment Total Copper Concentration
(Mean and Range)
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5 8 18a 2 19 20 6 7 17 1 3 4 28 W6
Pond Number
Co
pp
er C
on
cen
trat
ion
, mg
/kg
AET 1,300
AET 390
Source of Copper in Sediment
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000C
uS
O4
/OM
-10 0 10 20 30 40 50 60 70
Copper treatments 2006-2009
To
tal
Co
pp
er/O
M
R2 0.83
Part II summary• Fill soils and underlying pond sediments have elevated
phosphorus concentrations which explain some variability between pond “symptoms”.
• Sediment sources will be difficult if not impossible to control.
• Fill soil sources can be managed to some degree by minimizing leaching and surface water connections.
• Significant reductions in nutrient inputs and soil leaching can be attained by reducing irrigation.
• Copper concentrations in some pond sediments are high and likely effecting some aquatic organisms based on EPA listed Apparent Effect Thresholds (AET).
• Source of copper in sediments is most likely from copper sulfate treatments.
What Next?
• Continue LSP treatment ponds (6, 7, 17) with the following modifications– Exotic and nuisance emergent
management– Low density stocking of carp– As needed algae control
• Develop quantitative acceptability threshold to guide operations manager and contractor
Floating Treatment Wetland?
Beemats, - New Smyrna Beach, FLACF Inc., Jacksonville, FLHidrolution, Spain
PositiveLikely improve water quality, suppress SAV, algae Avoids homeowner shoreline
UncertaintiesTreatment efficiencies unknownNo direct suppression of filamentous algae along littoral shelf Optimization (harvesting) unknown