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 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 Treatments Carp Control / SAV Copper Sulfate Littoral Shelf Planting Aeration

Monitoring Methods Monthly monitoring Volunteer Observation August 13,2009 -January 15, 2010 Volunteer Observation SAV cover (% floating, % submerged), Water Clarity (scale 1-5) Aquatic life assessment (none = 0, infrequent = 1, common = 3, abundant = 10) Water sample NOx, TKN, TP (TN, TP, TN:TP) Photo Interpretation Floating filamentous algae (% cover) Emergent (% exotic, % native) Color/Clarity index (scale 1-5

Survey Data Sheet

Example Photo Interpretation

Import image to Coral Point Count Program

Overlay 100 random points and classify 36% open water 15% floating filamentous algae 5% native emergent 42% exotic emergent

Color/Clarity Index - #1 Clear, no green color

Color/Clarity Index - #2 Clear, some green color

Color/Clarity Index - #3 Slightly cloudy, strong color

Color/Clarity Index - #4 Strong Cloudy, Strong Color

Color/Clarity Index - #5 Visible particles, bright color

Part I Effects of Grand Haven Stormwater Pond Alternative Treatment Practices on Algae, Water Quality and Aquatic Life

Findings - Which of the 4 pond treatment methods was the most effective in controlling algae? Which of the 4 pond treatment methods was the least effective in controlling algae? 13.7% 34.3% 16.8%

Floating and Submerged SAV

Water Clarity and Color/Clarity Index

Native and Exotic Emergent Vegetation

Zooplankton Abundance

Snail Abundance

Insect Abundance

Fish Abundance

Reptile and Amphibian Abundance

Bird Abundance

Water Column Total Nitrogen

Water Column Total Phosphorus

TN:TP Ratio

Treatment Alternative/Study Cost

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 Water, Soils and Sediment

Methods Upland Soils – Mehlich-1 extractable P Fertilizer Application – Austin Outdoor Reclaimed Water - CDD Sediment – Ponar dredge Analysis for TP, TCu, Water extractable P

Spatial heterogeneity in soil phosphorus concentration 77% of soils sampled – no phosphorus fertilizer recommended Spatial heterogeneity in soil phosphorus concentration

Fill Soils Phosphorus Concentration Native Soil Fill Soil

Fill Soil Phosphorus Inputs 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 2009 57 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

Reclaimed Water Nutrient Inputs Average Rainfall 48.9 in Estimated irrigation need 20-35 in 1180 lbs 31 lbs Fertilizer 2009

Sediment Phosphorus Concentration

Sediment Phosphorous Inputs

Sediment Copper Concentration AET 1,300 AET 390

Source of Copper in Sediment Total Copper/OM 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, FL ACF Inc., Jacksonville, FL Hidrolution, Spain Positive Likely improve water quality, suppress SAV, algae Avoids homeowner shoreline Uncertainties Treatment efficiencies unknown No direct suppression of filamentous algae along littoral shelf Optimization (harvesting) unknown