The Leonhardt Lagoon The Leonhardt Lagoon at Fair Parkat Fair Park

A review of current water qualityA review of current water qualityand guidelines for remediationand guidelines for remediation

Presented byPresented by

David Jones, KHADavid Jones, KHAKoi & Water Garden Club of North TexasKoi & Water Garden Club of North Texas

HistoryHistory

When Patricia Johanson first visited Fair When Patricia Johanson first visited Fair

Park Lagoon in the 1980’s, years of local Park Lagoon in the 1980’s, years of local

lawn fertilization had washed fertilizer into lawn fertilization had washed fertilizer into

the lagoon, causing algal bloom. the lagoon, causing algal bloom.

A green slime covered the water, and A green slime covered the water, and

there were hardly any plants or animals . . there were hardly any plants or animals . .

1980’s Renovation1980’s Renovation

Major refurbishment 1980’sMajor refurbishment 1980’s Lagoon dredged, eroding banks rebuilt Lagoon dredged, eroding banks rebuilt

Concrete structures were builtConcrete structures were built

Restocked with native species of plants & fishRestocked with native species of plants & fish

Perimeter trail became a “living exhibit”Perimeter trail became a “living exhibit”

The Lagoon became a jewel in Fair ParkThe Lagoon became a jewel in Fair Park

Current Water Quality IssuesCurrent Water Quality Issues

Uncontrolled algae growthUncontrolled algae growth

Decomposing plant life is adding to bio loadDecomposing plant life is adding to bio load

High CO2 and Hydrogen Sulfite levelsHigh CO2 and Hydrogen Sulfite levels

Dissolved oxygen is low Dissolved oxygen is low

City water additions are harmful to fish and City water additions are harmful to fish and

other organismsother organisms

Green Slime Algae 8/18/06Green Slime Algae 8/18/06

Green Slime Algae 8/18/06Green Slime Algae 8/18/06

What is The Status Quo?What is The Status Quo?

Algae problems are increasing Algae problems are increasing

Water quality has deteriorated due to runoff and Water quality has deteriorated due to runoff and

cumulative effects of many issuescumulative effects of many issues

The Lagoon is now in ecological decayThe Lagoon is now in ecological decay

Stagnant water body with no flow and no turnover Stagnant water body with no flow and no turnover

Low oxygenation levels have led to an unhealthy Low oxygenation levels have led to an unhealthy

lake condition known as eutrophicationlake condition known as eutrophication

What is Eutrophication?What is Eutrophication?

It is a condition in an aquatic ecosystem where high nutrient It is a condition in an aquatic ecosystem where high nutrient

concentrations stimulate blooms of algae - phytoplankton.concentrations stimulate blooms of algae - phytoplankton.

This enhanced plant growth, often called an algal bloom, This enhanced plant growth, often called an algal bloom,

reduces dissolved oxygen in the water when dead plant reduces dissolved oxygen in the water when dead plant

material decomposes and can cause other organisms to die.material decomposes and can cause other organisms to die. This condition creates water with a low concentration of This condition creates water with a low concentration of

dissolved oxygen and is not a suitable habitat for fish or dissolved oxygen and is not a suitable habitat for fish or

other lake organismsother lake organisms

The Start of Lake Decay

Eutrophic Body of WaterEutrophic Body of Water

CO2 H2SO4

Anaerobic Bacteria

Algae Blooms in The LagoonAlgae Blooms in The Lagoon

Copper Sulfate treatment used in early August Copper Sulfate treatment used in early August

to rid the Lagoon of unsightly algae blooms to rid the Lagoon of unsightly algae blooms

Chemical treatment destroyed the algae bloom Chemical treatment destroyed the algae bloom

but had detrimental effects but had detrimental effects

Dead and decaying algae and plant material Dead and decaying algae and plant material

will worsen the eutrophic conditionwill worsen the eutrophic condition

Copper Sulfate is NOT bio-degradable and may Copper Sulfate is NOT bio-degradable and may

have undesirable side effectshave undesirable side effects

Effects of Copper SulfateEffects of Copper Sulfate

Copper Sulfate kills algae Copper Sulfate kills algae

Copper Sulfate kills plantsCopper Sulfate kills plants

Copper Sulfate kills fish eggs and fryCopper Sulfate kills fish eggs and fry

Algae sinks to bottom and starts to decayAlgae sinks to bottom and starts to decay

Decaying plant materials provide nutrients for Decaying plant materials provide nutrients for

new crop of algae . . . it’s a vicious circle!new crop of algae . . . it’s a vicious circle!

Copper Sulfate Sprayed 8/06Copper Sulfate Sprayed 8/06

Summary of Present ConditionsSummary of Present Conditions

Large body of water with no circulationLarge body of water with no circulation Runoff from surrounding areas adds nutrientsRunoff from surrounding areas adds nutrients Ineffective water mixing by fountainIneffective water mixing by fountain Algaecides have added to present conditionAlgaecides have added to present condition Water stratifies - warm upper and cooler deeperWater stratifies - warm upper and cooler deeper Lots of decay processes in deeper waterLots of decay processes in deeper water Very low D.O. in deeper water can’t support lifeVery low D.O. in deeper water can’t support life The whole water column needs remediationThe whole water column needs remediation

New Water Quality GoalsNew Water Quality Goals

Introduce top to bottom circulation to water by Introduce top to bottom circulation to water by using aeration to add oxygen to deeper waterusing aeration to add oxygen to deeper water

Add routine enzymes to dissolve decaying muckAdd routine enzymes to dissolve decaying muck Use non-chlorinated water supply from AquariumUse non-chlorinated water supply from Aquarium Replant marginal plant areas – let Nature work Replant marginal plant areas – let Nature work Water quality program to monitor progressWater quality program to monitor progress No further chemical treatmentsNo further chemical treatments

Problem - SolutionProblem - Solution

Storm water runoff/fertilizersStorm water runoff/fertilizers Recurrent Algae bloomsRecurrent Algae blooms Dead plants from chemical sprayDead plants from chemical spray High level of nutrients from decaying plantsHigh level of nutrients from decaying plants Minimal circulationMinimal circulation Low dissolved oxygenLow dissolved oxygen Water supply issueWater supply issue

Water SupplyWater Supply

Aquarium’s well has high capacityAquarium’s well has high capacity Previous history – used Aquarium water Previous history – used Aquarium water

maintained a constant level in the Lagoonmaintained a constant level in the Lagoon Transfer pipe was damaged in mid 1990’sTransfer pipe was damaged in mid 1990’s Since then, falling water level augmented by Since then, falling water level augmented by

city water (chlorinated)city water (chlorinated) Aquarium wastes useable water in sewerAquarium wastes useable water in sewer

Circulate Water With Aeration

Aeration in ActionAeration in Action

Aeration RemediationAeration Remediation

Action TimelineAction Timeline

Survey the lagoon for silt buildup and bottom Survey the lagoon for silt buildup and bottom

depth – needed to select oxygenation equipmentdepth – needed to select oxygenation equipment

Choose site for air pump cabinet, plumbing, GFI Choose site for air pump cabinet, plumbing, GFI

wiring etc, for aeration locations in the lagoonwiring etc, for aeration locations in the lagoon

Install air pump equipment in accessible locationInstall air pump equipment in accessible location

Add enzymes to help dissolve muckAdd enzymes to help dissolve muck

Establish supply from Aquarium to use “good” Establish supply from Aquarium to use “good”

water which is dumped in the sewer at presentwater which is dumped in the sewer at present

Aeration Equipment in BoxAeration Equipment in Box

What’s Next?What’s Next? Engineering drawings of LagoonEngineering drawings of Lagoon

Boat access to water for survey of lake bottomBoat access to water for survey of lake bottom

Choice of equipment needed based on surveyChoice of equipment needed based on survey

Final agreement on plan – and CoCFinal agreement on plan – and CoC

Funding for equipment purchaseFunding for equipment purchase

Equipment installation by Park staff and meEquipment installation by Park staff and me

Water supply from Aquarium establishedWater supply from Aquarium established

Update Nature Trail Update Nature Trail

DiscussionDiscussion