Part II: Water Quality

Water quality refers to the condition of the water: Is it clean or is it polluted?

Water needs to be clean enough to use the way we want to. Drinking water needs to be cleaner than water that is used only for recreation.

Water used for fishing and swimming must be clean enough to protect people’s health.

Water must also be clean enough to protect the health of animals and plants that depend on it for survival. Water is an essential part of any habitat.

Water pollution is divided into two kinds: Point Source Non-Point Source

Point Source Pollution Comes out of a Pipe

Nonpoint Source Pollution Erosion (Sediment) Animal Waste (Nutrients)

Construction

Sediment harms fish and other creatures.

Lawn Fertilizer

Animal Waste

Healthy Habitat Unhealthy Habitat Sunlight Small amounts of Nitrogen Phosphorous and sediment Large amounts of Nitrogen Phosphorous and sediment Healthy Bay Grasses Balanced Algae Growth Plenty of Oxygen Algae Bloom Sunlight No Oxygen Algae Die-off Algae Decomposition Reduced Bay Grasses

Shopping Center

Gas Station

You depend on your watershed for good, clean water.

Testing, or monitoring, water quality is needed to make sure that water is clean enough for human and animal health.

Water testing is divided into two kinds: Biological testing Chemical testing

Biological Monitoring Biological monitoring is a way to test the water quality of a stream by finding out what kind of benthic macroinvertebrates are living in the stream. benthic means, “living on the bottom of a body of water (such as a pond or stream)” macro means, “big enough to see” invertebrate means, “without a backbone”

Some Benthic Macroinvertebrates that live in streams

By finding out what kinds of macroinvertebrates live in a stream, you can determine how good the water quality is.

Sensitivity to Pollution Mayfly larvae are very sensitive to pollution. Horsefly larvae are tolerant of pollution. Dragonfly larvae are somewhat sensitive to pollution.

Most macroinvertebrates living on the bottom of streams are the larval stage of adult insects. Mayfly Larvae Mayfly Adult

To monitor a stream’s health, we collect macroinvertebrates from stream riffles.

Another Riffle

Collect macroinvertebrates from a stream riffle using a kick seine.

Carefully carry the net back to shore after collecting the macroinvertebates.

Identify and count all the macroinvertebrates

Most of them are very small.

Some of the bugs are a little bigger! These are two hellgrammites.

This is a stonefly larvae.

A water quality index score is calculated based on the: Kinds Number Diversity Of macroinvertebrates found in the sample.

Chemical Monitoring

Chemical monitoring is a way to check the water quality of a stream by performing various tests. Common tests are: Temperature pH Dissolved Oxygen (DO) Nitrates Turbidity Bacteria (E.coli)

Temperature A thermometer is used to measure water temperature. Living things need a fairly constant temperature to be healthy. Most living things are healthiest in a certain range of temperature.

Optimal Temperature Ranges for Wildlife Above 20°C Above 20°C (68°F) Bass, bluegills, carp, catfish, crappie, Dragonflies, trueflies, netspinners Cool Range Between 13 and 20°C Cool Range Between 13 and 20°C ( °F) Chinook, sturgeon, shad, walleye Maflies, caddisflies, stoneflies Cold Range Below 13°C Cold Range Below 13°C (55.4°F) Steelhead, sockeye, rainbow trout, brown trout, brook trout, smelt Maflies, caddisflies, stoneflies Warm Range Cool Range Cold Range Above 25°C Above 25°C (77°F) Lethal temperatures for salmonids and some aquatic insects

Temperature Native Brook Trout prefer a temperature below 13°C (55°F)

Temperature Rainbow Trout and Salmon prefer a temperature from 13°-20°C (55°- 68°F)

Temperature Perch and Catfish prefer water above 20°C (68°F)

Temperature Green algae bloom at a temperature above 25°C (77°F) Lake Meade, Nevada beforeafter

Factors that Influence Water Temperature 1.darker water is warmer because it converts sunlight to heat 2. overhanging trees shade streams and keep the water cool in summer 3. runoff from paved surfaces (like roads and parking lots) is warmer than runoff from grass or a forest floor

pH pH is the measure of alkalinity or acidity of a substance such as soil or water. a pH below 7 is acidic a pH above 7 is alkaline a ph of 7 is neutral

pH tolerance for most aquatic life All fish DEAD

pH Most aquatic organisms exist in a pH range of 5.5 to 9.5. Trout live in water that has a pH from 4.5 to 5.5.

pH The healthiest range for fish eggs is a pH from 6.0 to 7.2.

pH The best range for the growth of algae is 7.5 to 8.4. Is that acidic or alkaline? An algae bloom in Lake Meade, Nevada

pH Carp die in five days if the pH is 4.3 or lower. Is that acidic or alkaline?

Dissolved Oxygen (DO) DO is the measure of the amount of oxygen that is dissolved in the water. Oxygen enters the water in two main ways: plants turbulence

All Animals (Including Fish) Need Oxygen to Live Most aquatic animals, such as fish and macroinvertebrates, will die in a few hours at DO levels as low as 2.0 ppm Fish grow and develop more slowly at DO levels below 5.0 ppm. Most fish will die in a few days at DO levels below 3.0 ppm. DO ranges from 0 to 14 ppm.

How to Measure DO Dissolved oxygen is measured using a test called the Winkler Method. Use gloves while collecting the sample and conducting the test to avoid contamination of the water sample and to protect your hands Wear glasses or goggles to protect your eyes.

Other Chemical Tests Other chemical tests that are useful can measure the following: nutrients such as nitrogen and phosphorous bacteria from animal and human waste turbidity is how cloudy the water appears toxic substances such as pesticides, metals and various chemicals

Turbidity Turbidity is a measure of the “cloudiness” of water. Cloudiness is caused by suspended solids (mainly particles of soil) and plankton (microscopic plants and animals) A healthy stream may have moderately low levels of turbidity because plankton are an important part of the food chain.

Turbidity Clay and silt particles produce most of the turbidity in this picture.

Turbidity Higher levels of turbidity can cause problems: Turbidity blocks out sunlight needed by submerged water plants. Turbidity can raise water temperature by absorbing the heat of sunlight. Turbidity can make it harder for creatures to find food.

The secchi disk is lowered on a line marked for depth, and the depth at which it disappears is recorded to measure turbidity. Turbidity

Nitrate is the first nutrient listed in a fertilizer. The numbers ( ) indicate the percent by weight of each nutrient. Nitrates

BACTERIA Most bacteria are important in nutrient and other biological cycles. Excess nutrients cause algal blooms. As algae die and decay, the high bacterial load rapidly consumes dissolved oxygen. Fish kill due to low dissolved oxygen.

BACTERIA Some bacteria can make people sick when they drink the water, or cause infections when people swim in it.

2134 Berkmar Drive Charlottesville, VA Thomas Jefferson Soil & Water Conservation District