Teacher Preparation Guide

Phinizy Swamp Nature Park Program: Teacher Field Trip Preparation Guide

Program: Wastewater Ecology

Objectives: To learn that water is a precious and limited resource that communities need to adequately clean, and to learn the methods the city of Augusta uses to clean its wastewater

Vocabulary:

Aerobic: Able to live, grow or take place only where free oxygen is present
Anaerobic: Able to live, grow, or take place only where there is no or low free oxygen
Bacteria: One-celled microorganisms with no chlorophyll that multiply by simple division, and may ingest dead material to live. Some bacteria cause disease in plants and animals.
Dissolved Oxygen: Oxygen that is dissolved in water and available for aquatic plants and animals (fish, macroinvertebrates, etc.) to breathe. It is measured in parts per million.
Effluent: Flowing out; the treated wastewater that leaves the wastewater treatment plant
Fecal Coliform: Non-pathogenic bacteria present in the gut of all warm-blooded animals; often used as an indicator of pollution by sewage or animal waste
Grit: large-textured sediment, such as sand.
Influent: Flowing in; the untreated wastewater that enters into the wastewater treatment plant
Microorganism: A microscopic animal or plant; mostly single-celled bacteria and protists (based on the 5 kingdom classification system)
Nutrients: Anything nutritious; an element or compound such as nitrates and phosphates necessary for plant growth and development
Pathogen: Any microorganism or virus that can cause disease
Scum: A thin layer of impurities, which forms on the top of liquids or bodies of water
Sludge: Solids and semi-solids that settle to the bottom of tanks during wastewater treatment
Tertiary treatment: A third step of wastewater treatment which includes filtration, nutrient removal, and removal of toxic chemicals or metals
Vortex: A whirling mass of water forming a vacuum at its center into which anything caught in motion is drawn. Used to remove grit.
Wastewater: Water that has previously been used and contains a mixture of water and dissolved or suspended solids
Weir: An obstruction placed in a stream, diverting water through a hole for controlling flow rate

Teacher Background Information: On Wastewater Treatment

What is wastewater?

Water that has been used in our homes (washing machine, dishwasher, shower, sinks, toilet)
Water that has been used by commercial business or industry(restaurants, grocery stores, schools, chemical plants, etc)
Water that goes down neighborhood storm drains

How can wastewater be treated?

These represent examples of how cities can clean wastewater. Some cities, such as Augusta , use combinations of some of these methods

Aerobic and anaerobic microorganisms to break down nutrients
Screens and settling tanks to remove solids and suspended solids
Chemicals such as chlorine to kill pathogens
Filters of carbon, sand, rocks, or gravel (often used in septic tanks)
Lagoons (through the action of sunlight, algae, microorganisms, and oxygen) - they are slow and relatively inefficient, but are cheap.
Wetlands, mainly as a tertiary treatment (as seen in Augusta )

Why should we treat our wastewater?

For State and National Governments. The Clean Water Act requires each source of water pollution to treat their wastewater as necessary to meet effluent discharge limits and performance standards set by the EPA before releasing the wastewater to a stream or lake. ( Augusta must also meet specification as set by the Georgia Environmental Protection Division.)
For our continued recreational (fishing, boating, swimming)
For our drinking water needs
For our neighbors who re-use the water that we have already used
For future generations

Summary of Augusta 's Messerly Wastewater Treatment Plant

The plant receives about 30 million gallons of wastewater on a normal day and 67 million on a rainy day. They have holding tanks for wastewater when too much is coming in.

Preliminary treatment

The influent arrives from Richmond County
Large inorganic material such as rocks and plastics are removed by a conveyor system and taken to the landfill
The wastewater then enters a grit removal system where a pump creates a vortex and the slower moving dirt or grit falls out of the water and is taken to the landfill
The wastewater is pumped by a lift station to a high level so it can flow downhill through the rest of the treatment process

Primary treatment to remove suspended solids

The wastewater enters a splitter box, and half is sent to the north tank and half to the south tank (same treatment at each)
As the water moves slowly from one end of the tank to the other, solids begin to drop out. Floating solids of mostly oily and fatty material called scum go to the top and what falls to the bottom is called sludge. A skimmer removes the scum and sludge from the water.
The scum is treated for pathogens and sent to the landfill.
The sludge is sent to an anaerobic digester where it is cleaned of pathogens and then sold to farmers as fertilizer. There is currently a waiting list for this fertilizer!
A weir at the end of the primary treatment diverts the wastewater to the secondary treatment

Secondary treatment

The wastewater enters an aeration basin where activated sludge is added. Activated sludge is a slurry of aerobic microorganisms which feed on the wastewater and break down the high concentrations of nutrients. The blowing building provides the oxygen. After this feeding frenzy, the microorganisms rest.
The aeration basin sends the wastewater/microorganism solution to the secondary clarifiers where the microorganisms fall to the bottom and rest.
Some of the wastewater and the microorganisms are sent back to the aeration basin for additional cleaning. The rest of the treated wastewater continues to the next step.
Chlorine is added to the treated wastewater to kill any pathogens.
The treated wastewater exits the plant and heads to the tertiary treatment (the constructed wetlands).

Environmental Lab

At the discretion of the wastewater treatment plant representative, some tours may include the environmental lab, which is in the main building at the plant. The environmental lab is responsible for testing the wastewater during the cleaning process. Tests include:

BOD biochemical oxygen demand: a measurement of the amount of oxygen that will be consumed by microorganisms during the biological reaction of oxygen with the wastewater
TSS total suspended solids: a measurement of the quantity of suspended solids ("dirt") present in wastewater
Fecal coliform: a measure of the amount of fecal material in the wastewater
Ammonia, phosphates, and nitrates: nutrients
pH: to determine if the water is within the proper range

Summary of Phinizy Swamp 's constructed wetlands

The constructed wetlands provide a tertiary treatment to the wastewater and are human-made. Our natural wetlands are far too valuable to use for wastewater treatment but act as a guideline for how our constructed wetlands should work.

Equalization Pond

The treated wastewater exits the plant and flows by gravity to the equalization pond.
As the water travels through the pond, the chlorine evaporates making the water safe for the wetland plants and any fluxes in nutrient amounts are equalized.
The orange curtain in the middle of the pond slows the water flow, insuring that the water stays in the pond for three days.

Distribution Canal

The treated wastewater exits the equalization pond and flows by gravity to the distribution canal.
Weirs along the distribution canal distribute the water to each wetland cell.
There are currently 12 wetland cells that each function identically.

Wetland Cell

Each 30-acre cell starts with a shallow marsh followed by a 3.5 to 4 foot deep pond and ends with another shallow marsh.
The first marsh is aerobic. Microorganisms that live on the plant stems and roots begin breaking down the organic matter and nutrients, such as ammonia, into safer elements such as nitrates and nitrites. Some of the nutrients are absorbed by the plants for growth. Phosphates and heavy metals bind to the clay particles in the soil at the bottom of the marsh, or are absorbed by the plants of the marshes.
The water then flows into the pond where anaerobic microorganisms further break down the nutrients. Nitrates and nitrites are broken into nitrogen gas which makes up about 77% of the air we breath.
The water then flows into the second marsh, which is to trap any suspended soil particles.

Clarifying Pond

Each wetland cell sends its water to a common clarifying pond.
Here suspended soil particles that may still be present fall out.
The water exits the pond and enters a ditch, which leads to Butler Creek and then to the Savannah River .

On Wetlands: What is a wetland?
A wetland is just that, wet land. A wetland is an area that has all three of the following characteristics:

Low-oxygen (anaerobic), hydric (water-saturated) soil
Special hydrophytic (water tolerant) plants that can survive in low-oxygen conditions
A hydrologic regime where water is frequently at, just below, or just above the ground’s surface, creating saturated conditions that lead to the development of hydric soils and the presence of hydrophytic plants ( the level of water often fluctuates and is far from constant)

Where are wetlands located?

All over the world and in every state in the U.S
They can be freshwater or saltwater
They can be along a body of water or independent from another water source
They are often transitional areas located between dry land and deeper aquatic systems such as rivers and lakes
They can be forested or not forested
5% of U.S. wetlands are coastal wetlands, while 95% are inland wetlands

What are some examples of wetlands?

Marshes: dominated by herbaceous vegetation, with water levels from 3 feet to 6 inches or less. Includes salt marshes, fresh water marshes, and brackish marshes
Swamps : dominated by woody trees or shrubs
Wet meadows: a type of marsh dominated by grasses or sedges, with water levels at 6 inches or less
Prairie Potholes : water-filled glacial depressions located primarily in the mid-west. An important site for waterfowl
Bogs and Fens : wetlands with peat for soil due to low decomposition rates
Vernal Pools : Temporary pockets of water that fill depressions in wooded areas, meadows, and river floodplains
Carolina Bays : Unique wetlands found primarily in the coastal plain of North Carolina, South Carolina , and Georgia which are typically shallow, oval depressions

What wetlands exist at Phinizy Swamp Nature Park? Floodplain swamp (a swamp that exists near a stream or river) Constructed wetland marshes (human-made grassy wetlands) Oxbow Lakes and River Scars (remnants of where a river used to flow)

Why is it important to protect wetlands (values of wetlands)?

They improve water quality by intercepting surface runoff and removing nutrients, waste and sediment from water
They slow water down and prevent erosion
They soak up floodwaters thus preventing downstream floods
They provide areas of recreation and beauty
They provide essential habitat for many diverse and often endangered species. Up to 45% of threatened or endangered species rely on wetlands for their survival
They furnish natural products such as food, timber, fur to humans
Some help to recharge groundwater supplies
They provide areas for education and research
Some wetlands support downstream aquatic systems
The U.S. has lost over 50% of our wetlands to agricultural conversion, mining, and urban development

Suggested Activities for before or after the field trip:

**Consider calling us for one of our loan boxes that matches with each field trip - they contain many fun activities for you and your students!

First have the students come up with their own definition of wastewater. Have the students brainstorm and make a list of where wastewater comes from and reasons for treating it. You may also have them discuss the functions of wetlands in helping to clean wastewater.
Have students identify areas of the globe where water is limited, plentiful, or in excess and discuss the geographical and climatic qualities contributing to these conditions. How do the inhabitants of these different areas treat water differently as a result of how much water is available. How might you treat water differently if the U.S. suddenly had less water to provide to its residents?