STORMWATER STORMWATER ISSUES & SOLUTIONSISSUES & SOLUTIONS

St. Andrew Catholic SchoolSt. Andrew Catholic SchoolMrs. DunneMrs. Dunne’’s 8s 8thth Grade Science ClassGrade Science Class

September 21, 2006September 21, 2006

Karen FussEducation Coordinator of Coastal Waccamaw Stormwater Education Consortium

A Watershed is an area of land that drains to a single outlet.

What is a Watershed?What is a Watershed?

Point Source Point Source PollutionPollution

NonpointNonpoint SourceSourcePollutionPollution

Impervious SurfacesImpervious Surfaces

Materials like cement, asphalt, roofing, and compacted soil that prevent percolation of runoff into the ground.

Components of Impervious Cover in the Urban LandscapeComponents of Impervious Cover in the Urban Landscape

Roads

ParkingParking

BuildingsBuildings

SidewalksSidewalks

DrivewaysDriveways

Center for Watershed Protection

Intensity of Land UseIntensity of Land Use

LikelihoodLikelihood of Water Quality Problemsof Water Quality ProblemsAmount of Impervious SurfaceAmount of Impervious Surface

Local Local StormwaterStormwater IssuesIssues

Beach SwashesBeach Swashes

Funnel Funnel stormwaterstormwater

into the oceaninto the ocean

Water QualityWater QualityMonitoringMonitoring

SC DHEC and CCU monitor SC DHEC and CCU monitor beach sites along Grand beach sites along Grand StrandStrand

Testing for the bacteria Testing for the bacteria enterococcienterococci –– pathogen pathogen indicatorindicator

Gastroenteritis symptomsGastroenteritis symptoms--nausea, vomiting, diarrhea, nausea, vomiting, diarrhea, ear, eye, skin, nose and ear, eye, skin, nose and throat infectionsthroat infections

Information For YouInformation For You

Check Before You GoCheck Before You Go

Problems Caused By NutrientsProblems Caused By Nutrients

What are sources?What are sources?

What do nutrients do?What do nutrients do?

What happens after algaeWhat happens after algaedies?dies?

Harmful Algae Harmful Algae -- CyanobacteriaCyanobacteria

BlueBlue--green algae that green algae that fish will not eatfish will not eat

Found in turbid and Found in turbid and nutrient rich waternutrient rich water

Prefer high temperaturesPrefer high temperatures(>25(>25ooC or >77C or >77ooF) F)

Increasing occurrenceIncreasing occurrence

Some produce toxinsSome produce toxins

Can affect humans and dogsCan affect humans and dogsSkin Skin -- rash, hives, or blistersrash, hives, or blisters

Inhaling Inhaling -- sore throat, asthmasore throat, asthma--like like symptoms, or allergic reactionssymptoms, or allergic reactions

Swallowing water Swallowing water –– gastroenteritis, gastroenteritis, liver and kidney toxicity, numbnessliver and kidney toxicity, numbnessand tingling, dizzinessand tingling, dizziness

In DogsIn Dogs•• Salivation, weakness, staggering, difficulty Salivation, weakness, staggering, difficulty

breathing, convulsions, and death breathing, convulsions, and death

Illnesses From Exposure to Illnesses From Exposure to CyanotoxinsCyanotoxins

Sediment LoadingSediment LoadingRemoved from streets and construction sitesRemoved from streets and construction sites

Problems Caused By SedimentProblems Caused By Sediment

What are the effectsWhat are the effects?

Pathogens Pathogens –– disease causing bacteria & disease causing bacteria & viruses associated with fecal matterviruses associated with fecal matter

From whom?From whom?

Problems Caused By PathogensProblems Caused By Pathogens

Problems Caused By Toxic Problems Caused By Toxic ContaminantsContaminants

WhatWhat are the effects?are the effects?

What are the sources?What are the sources?

Problems Caused By DebrisProblems Caused By DebrisGrass clippings and other Grass clippings and other yard wasteyard waste

Other trashOther trash

Thermal StressThermal Stress

High temperatures can affect native species High temperatures can affect native species and promote nonand promote non--native speciesnative species

Impervious runoffImpervious runoffNo vegetative buffersNo vegetative buffers

Stormwater Management PracticesStormwater Management Practices

Photos: D. Hitchcock

What is a Best Management What is a Best Management Practice (BMP)?Practice (BMP)?

SC DHEC says a BMP isSC DHEC says a BMP is……a management and conservation a management and conservation practice that has been demonstrated practice that has been demonstrated to effectively control movement of to effectively control movement of pollutants, prevent degradation of soil pollutants, prevent degradation of soil and water resources, and are and water resources, and are compatible with the land usecompatible with the land use

Strategy for coping with polluted runoffStrategy for coping with polluted runoffStrategy for coping with polluted runoff

Types of Stormwater Types of Stormwater BMPsBMPs

Infiltration (pervious surface materials and sand Infiltration (pervious surface materials and sand filters)filters)

Filtering (Filtering (bioretentionbioretention areas and rain gardens)areas and rain gardens)

Open Channel (grassed swales)Open Channel (grassed swales)

Stormwater WetlandsStormwater Wetlands

InIn--line Devices (trash traps line Devices (trash traps and pollutant and pollutant adsorbersadsorbers))

Stormwater PondsStormwater PondsStormwater Ponds

Photo: Susan LibesPhoto: Dan Hitchcock

Photo: Dan Hitchcock Photo: Dan Hitchcock

Functions of Functions of StormwaterStormwater PondsPondsTo hold and move waterTo hold and move water

Manage Manage stormwaterstormwater quantity,quantity, but NOT but NOT qualityquality

Remove sediment and solids, but NOT Remove sediment and solids, but NOT nutrientsnutrients

• Vegetated buffer strips

• Don’t mow to the edge

• Stormwater collection and pre-treatment

• Littoral shelves or aquatic “benches”

Stormwater PondsBuffers

Vegetated Riparian (shoreline) Buffers

Select Benefits:• Combat erosion/ stabilize shoreline• Slow overland flow/ enhance infiltration

* facilitates groundwater recharge• Trap and retain sediment• Take up excess nutrients• Remove contaminants• Provide shade and natural habitat

Photo: D. Hitchcock

BioretentionBioretention / / Rain GardensRain Gardens

• For any impervious surface(rooftop, sidewalk, parking lot)

• Allows collection ofstormwater and infiltration

• Plants and microbes do the work of pollutant removal

• Can be attractor for wildlife such as birds and butterflies

Photo: Center for Watershed Protection (www.cwp.org)

Photo: NC State Cooperative Extension(www.bae.ncsu.edu/stormwater)

Source: Bill Hunt, NCSU

BioretentionBioretention / Rain Garden / Rain Garden SchematicSchematic

EARTH FILL -Primarily Sand

Underdrain System

Vegetation on SurfaceVegetation on SurfaceRunoff

Open Channel Open Channel ––Swales, Ditches, CanalsSwales, Ditches, Canals

• Allows relatively rapid conveyance of stormwater

• Slows flow to allow sedimentsettling and some infiltration

• Can be attractor for wildlife and associated bacteria

Photo: Susan Libes

Benefits from Using Benefits from Using Stormwater WetlandsStormwater Wetlands

• Good nutrient removal

• Aesthetically pleasing

• Provides natural wildlife habitat

• Relatively low maintenance costs

• Relatively low operations costs and energy use

• Great educational tools!

• Mosquito issues

• Invasive vegetation

• Nuisance “critters”

• Odor can be an issue

• Needs continuous baseflow for viable wetland

• Sediment regulation is critical to sustain wetlands

Limitations to Using Limitations to Using Stormwater WetlandsStormwater Wetlands

Rain BarrelsRain Barrels

Re-route runoff to vegetated/ pervious areas

What Can YOU Do?What Can YOU Do?

Use what you have learned today at Use what you have learned today at home, at school and in your neighborhoodhome, at school and in your neighborhood

Teach your parents and neighborsTeach your parents and neighbors

Develop an action plan and implement itDevelop an action plan and implement it

JUST DO IT JUST DO IT –– YOUYOU CAN MAKE A CAN MAKE A DIFFERENCE!DIFFERENCE!