Mother Nature’s Treatment Methods: Using Passive Treatment for a Variety of

Wastewater StreamsBrian Tornes, PE

History of Wastewater TreatmentBackground

The Start of Sanitation

Evidence of Sewers as Far Back as 8000 BC

Cesspits 4000 BC

Lothal, Western India 2500 B.C.

Rome’s Advances

Combined Sewers at their best

Regression of the Middle Ages

Treatment During This Time

Dilution was the solution

Downstream users’ problem

Natural breakdown of wastes

Population Explosion

Rapid Growth

Concentrated Populations

Home Conveniences

Health Issues

Understanding the Need for Treatment

Plague of Justinian Black Death Bubonic Plague Yellow Fever Cholera Typhoid FeverHepatitisMalaria

First Attempt at Sanitation – Bury the Problem

1800 – 1900s Pits

Advent of Modern Wastewater Treatment

Primary Treatment

Secondary Treatment Activated Sludge

Tertiary Treatment Filtration

Insert WWTP photo

Needs of a Treatment Plant

Infrastructure (Tanks, pumps, piping, aerators)

POWER (and lots of it)

Sludge Disposal Mechanism

Maintenance

Passive TreatmentAn alternative to conventional treatment systems

Types of Passive Treatment

Constructed Wetlands Surface and subsurface

Phyto-Treatment Use of trees

Potential Benefits

Low Electrical Energy Requirement

Function Under Both High and Low Loading Rates

Low Operating Cost

Constructed WetlandsAn alternative to conventional treatment systems

Constructed Wetlands – How do they work?

Wetland Case Study: Camp Otterbein

Owned by United Methodist Church in Logan, Ohio

Summer Camp/Weekend Retreats

Capacity for 180 guests

Wastewater Treatment at Camp Otterbein

1950’s Package Plant for 10,000 gpd

Secondary Level Treatment

Poorly Maintained Operation

Design Loading

Hydraulic Loading : 10,000 gpd Water meter: 0 – 5,400 gpd (7,600 gpd peak) High storm water inflow and infiltration

BOD : 220 mg/l TSS : 220 mg/l

Wastewater Handling Alternatives

Pump to Logan (2 miles)

Activated Sludge Process with Sand Filtration/Disinfection

Activated Sludge with (0.3 Acre) Constructed Wetland

Septic Tank(s) with Constructed Wetland

Remote Treatment Problems(Packaged Treatment Plant)

Poor Maintenance Equipment failures No operation adjustments

Power Failures

Load Fluctuations(Upsets) Ineffective treatment

Why Pay More for Wetlands

Replaces Dosing Chamber, Sand Filters, Disinfection

Wetland Advantages Excess solids removal Excess nutrient/BOD uptake Handles fluctuating loads Low maintenance Natural setting

Septic vs. Activated Sludge

Septic Pretreatment Concerns

Odor

Higher solids loading to wetland

Nitrogen Loading Much larger wetland is required (10-12 times)

System Flow Diagram

Activated Sludge Process

Wetland Design Features (Configuration)

Rectangular Avoid short-circuiting Low velocity

Inlet/Outlet Features

Even Flow Distribution Level Adjustment Capabilities Liner Protection

Wetland Design Features (Liner)

Cross Section Liner: Clay vs. GCL 12” Topsoil

Wetland Construction – 1 year to maturity

Concerns with Constructed Wetlands

Low Dissolved OxygenGetting Plants Established Algae GrowthNatural Decomposition of

Plant Material Stormwater EntryWildlife (Muskrat)

Phyto-TreatmentAn alternative to conventional treatment systems

Phyto-Treatment (Phytotechnology Mechanisms)

Phytosequestration Rhizodegradation Phytohydraulics Phytoextraction Phytodegradation Phytovolatilization

*Phytotechnology Technical and Regulatory Guidance and Decision Trees, Revised (ITRC, February 2009)

Watson Road Landfill

Existing Conditions

NPDES Permit Exceedances Landfill Cap Erosion Leachate/Groundwater Interim/Daily Cover/Leachate

Newark Watson Road Landfill

WesternUnnamedTributary

DegradedCap

AccessRoad

MunicipalSolid Waste

Leachate/Groundwater

Interim / Daily Cover

Landfill Cap

Precipitation

Leachate/Groundwater Increases

Precipitation

Secondary LeachateAccumulates

Cap ErodesLeachate Seeps Form

Formation of Wetland-Type Vegetation

Landfill Cap SaturatesUpgradient Leachate Seeps Provide Further

Saturation Erosion Channels FormWetland-Type Vegetation Grows

Wetland Development

Landfill Cap Becomes Saturated

Wetland-Type Vegetation Grows

Erosion of Toe of Landfill Slope

Surface Water Has Eroded Toe of SlopeWaste Exposed Leachate Discharge Points Formed

Landfill Toe Erosion

Leachate Management Alternatives

Pump and Treat Cap repairs Cut-off wall Pump over 1 mile to

City WWTP Variable leachate

volume Expensive

Phyto-Treatment Cap repairs Tree planting to reduce

leachate volume Treatment buffer to

meet limits Continued NPDES

discharge Lower costs

Recovery Wells/Horizontal Trench

Install Water Recovery Wells or Horizontal Trench SystemOnsite Leachate Storage Tank(s)Onsite Wetland Treatment Cell(s)/MitigationWastewater Line Formal Leachate Collection System - Additional

Regulatory Requirements

Alternative Remediation (Recovery Wells)

Alternative Remediation (Recovery Wells)

Onsite WetlandRemediation Cell

LeachateStorage Tanks

Recovery Wells

Offsite Wastewater Line

The Solution - Phyto-Cap

Planting Over 3,000 Willows and Poplars Inter-Planting of Another 300 Native Hardwoods

And E-Buffer

Evapotranspiration Subsurface FiltrationMicrobial Activity at the

Root Zone

Phytoremediation

Operational Concerns

Up to 5 Years for Maturity Compliance Sampling Access Deer Insects Voles

Results

Deer – Required replanting of 80% of trees with deer guards

241 NPDES exceedances between 2003 and 2009 (72 for ammonia)

Since installation in 2012, only 3 minor exceedances, none of which were for ammonia

Estimated capital cost savings of $3.5 Million over traditional collect and pump

Operational savings still growing

Passive Treatment

Not for all waste streams, but where opportunities exist…

Landfill Leachate Stormwater RunoffGroundwater Remediation

(Including PCBs) Acid Mine Drainage

(metals treatment) Small Capacity Sanitary

Wastewater

Alternative Treatment Streams

Questions?Thank you!