Mudboils AEES Pre-Conference Workshop Wednesday, June 6, 2012 Nate Barlet Brandon Winfrey Roy Wood

Problem Statement Turbidity in Onondaga Creek too high to support species historically present Sediment load to the creek from mudboils has been identified as major contributor to turbidity Turbidity in Onondaga Creek too high to support species historically present Sediment load to the creek from mudboils has been identified as major contributor to turbidity

Goals and Objectives Improve Onondanga Creek to support fish species present upstream of the mudboils – Intercept 100% of sediment load from mudboils. This will protect river ecosystem from ever being affected by mudboil sediments that increase turbidity

Design Constraints Landowner – Honeywell Hydrogeology – Unclear Environmental Energy Cost – Dredging may be required

Potential Solutions (1) One Large Relief Well – Attempt to create mudboil in the existing area to control source of sediment “One Well to Rule them All” Advantages: Control source Easier to design sediment abatement Disadvantages: Unclear if control is possible Low flexibility if other mudboils appear

Potential Solutions (2) Divert Creek around mudboils, Contain mudboils – Build impoundment around entire area – Move creek channel into field adjacent Advantages: Creek avoids sediment loading (never impacted) Mudboils potentially capped by hydraulic head Disadvantages: Expensive May create mudboils down gradient Creek channel may migrate back to mudboil area

Potential Solutions (3) Impoundment around rogue mudboil, Wetland for smaller particle removal, relief wells – Build impoundment around rogue mudboil followed by wetland – Surround impoundment by relief wells – Construct levee to protect creek Advantages: Protects creek from incoming sediment Provides ecological and aesthetic service Flexible design Disadvantages: Storm events could decrease sediment capacity Annual dredging required Large land area required

Design Overview Relief Wells assumed to control flow from mudboils to not exceed 400 gpm Impoundment designed to contain particles > 4 μm Wetland designed to remove smaller particles (< 2 μm) Levee high enough to protect creek from storm events

Relief Well Design Install 4 relief wells surrounding impoundment berm – 5” diameter with screens excluding sand size particles – Installing 1 well next to mudboil can potentially reduce hydraulic head by 15 ft. – Install wells 20 ft. from mudboil vent to prevent intercepting sediment flow in vent

Impoundment Design (1) Dredging is unavoidable – Annual dredging – Design to remove 4 μm particles Settling velocity of 6 x cm/s 38 hr detention design driven by solids dredging annually, not settling time requirements

Impoundment Design (2) 35 meter diameter 6 ft high 3 feet water level design walls are 3 foot wide top, 3:1 slope, 13 ft bottom

Profile View: Impoundment Mudboil cone Drains to Wetlands

Wetland Design (1) Sheet flow over vegetation to remove particles smaller than 2 μm. 155 acres size driven by solids limit to 2 cm/yr depth <1 acre needed for solids removal retention time

Profile View: Wetland 4 % slope

Design Overview

Estimated Cost $45,000 based on $15/cu. yd. – Includes berms for access to impoundment and levee $5 million for bio-swale – Based on estimated cost per acre of $35,000

Other Considerations Problem of source too large to contain Salinity diluted in stream to lower levels – Salinity in relief wells presumed to decrease (drawing from freshwater aquifer) – Not included in treatment goal Snowfall my decrease residence time in winter Do relief wells control flow from mudboils to below historic high flows? – Studies on effects of relief wells on mudboil flow should be done Pilot-scale study on effectiveness of wetland – Vegetation response to sediment over time – Fine particle removal rates Construction should occur in phases – Install relief wells first, allow some time for mudboils to react (1-2 years) – Build levees and impoundment around stabilized mudboils (1-2 years) – Construct wetland, route water from impoundment through wetland (20-year design life)

Summary As designed, sediment load from mudboils intercepted before entering Odondanga Creek – Ecological buffer (wetland) between mudboils and creek should enhance recovery of fish populations – Levee would prevent resuspension and conveyance of sediment to creek during storm events – While dredging required, sediment has astringent qualities that could have market value as a cosmetic product

Questions?