Lecture 5 - Water Quality

two key questions:

How do changes in management decisions impact water quality?

How does water quality influence management decisions?

watershed management objectives

1. Maintain and/or increase yields.

2. Maintain and/or improve water quality. (this lecture)

• This is our focus this section, but all the other objectives ultimately impact water quality

3. Regulate timing of stream flow.

4. Control excessive soil erosion and excessive runoff.

Water quality is the physical, chemical, or biological characteristics of water where

the measure of water quality or standard refers to the characteristics of water in relation to a specific use

use of water quality management determines 

appropriate water quality standards

water quality can differ substantially between

water bodies, depending on their use (ex. drinking water, farming, fish habitat, industrial processing, swimming)

Specific Use =

Intended Use = Designated Use

Water quality standards is the basis we use to determine whether

that body of water has been degraded

water quality standard is expressed as maximum allowable

concentrations of specific pollutants

Land use impacts on water quality characteristics naturally occurring in surface water that are

impacted by non-point source pollution, rather than point source pollution

non point source pollution is associated with 

run-off from land use activities

• agricultural cultivation

• livestock grazing

• forest management

  • urbanization

what is the biggest contributor to water quality impairment for rivers and lakes in the US?

Agriculture

What is the biggest contributor to Water Quality impairment for Estuaries?

Runoff from Urban Areas

surface water characteristics

chemical

physical

biological

chemical: what is bioaccumulation

Process by which toxins build up in individual organisms

Usually at the base of the food web

• EX. phytoplankton

chemical: what is biomagnification

Process by which toxins are passed from one trophic level to the next, increasing in concentration

bioaccumulation and biomagnification often 

occur togther

different chemical pollutants

Endocrine Disruptors

PFAs

Nutrients

Heavy Metals

Pharmaceuticals

Microplastics

endocrine disruptors are compounds that

Produce adverse developmental, reproductive, neurological, and immune effects

• in both humans and wildlife

endocrine disruptors mimic

hormones: estrogens, androgens, thyroid hormones

works about pollutants

Silent Spring – by Rachel Carson, 1962

Our Stolen Future – by Theo Colborn, Dianne Dumanoski, and John Peterson Myers, 1996

endocrine disruptor sources include

Pesticides, plastic, metal food can liners, detergents, flame retardants, food, cosmetics

endocrine disruptors: effects from 2015 report by endocrine society 

Listed obesity, diabetes, male and female reproduction issues, hormone-sensitive cancers in females, prostate cancer, thyroid, and neurodevelopment and neuroendocrine systems as being affected by exposure to endocrine-disrupting chemicals

Some researchers – reduced IQ, ADHD, and autism

endocrine disruptors: they work because hormones

are chemical messengers in the body

• Work at very small doses (ppb levels)

• Very low levels already present

endocrine disruptors: edc’s bind to receptors for 

hormonally mediated processes

• very small amounts needed to produce adverse effects

• much smaller doses than for toxicity

endocrine disruptors: timing of exposure

Most critical stages of development occur in utero

Interference with hormonal communication can affect both structural and brain development

Depends on the stage of development

Difficult to find cause-and-effect with adult conditions and exposure in utero

endocrine disruptors: broad trends from emerging science

1. Exposure is everywhere

2. Impacts at levels far lower than in traditional toxicology

• Parts per billion or parts per trillion

3. Perhaps all chemically-mediated message systems are vulnerable to EDC

4. Many more compounds are known to be EDCs

5. Adult impacts from fetal exposure

• Traditional view – adult impacts from adult exposure

• Difficult to show cause-and-effect of adult impacts arising from fetal exposure

6. Human epidemiology is biased toward false negatives

• Stat term – finding no association when in fact there is one

• Traditional epidemiology research perspective

• Precautionary Principle may apply here

  • Social responsibility to protect the public from exposure to harm when scientific investigation has found a plausible risk

PFA’s (forever chemicals) are perfluoroalkyl and 

polyfluoroalkyl substances

1,000s of PFAs have been in use

since the 1940’s

PFA’s are widely used,

long lasting

• Break down very slowly

• Also known as “forever chemicals”

Found in blood of people and animals all over the globe

Present in food, water, air, fish, and soils

harmful health effects of PFAs in humans and animals

Altered metabolism

Fertility

Reduced fetal growth

Increased risk of obesity

Increased risk of some cancers (kidney and testicular)

Increased risk of Type 2 diabetes in women

Liver and thyroid problems

Impaired immune system

Sources of PFAs

nonstick cookware

water-repellent clothing

stain resistant fabrics and carpet

some cosmetics – nail polish, eye makeup

personal care products – shampoo, dental floss

products that resist grease, water, and oil

• pizza boxes, candy wrappers

• fast food containers and wrappers

• microwave popcorn bags

paints, varnishes, and sealers

what should we do about PFA’s?

no known treatments

• Reduced with high fiber diet and folate

can’t just run water through a water treatment facility to eliminate

Studies being conducted on phytoremediation

• Used with silica nanoparticles and carbon nanoparticles

No regulations that require disclosure by manufacturers

Some brands have voluntarily removed (or will be removing) from clothing

• American Eagle, LL Bean, Ralph Lauren, Patagonia

ongoing efforts to address PFAs include

EPA had been active

• Website now says ”Pros and Cons”

• Report summarizing EPA efforts (November 2024)

• Water quality standards for 10 PFAs (September 2024)

• Superfund designation for 2 PFAs (April 2024)

• Drinking water standards (April 2024)

Canada

• Actively trying to address – research and legislation

• Phase-in prohibitions

• Water quality standards

nutrients: excess levels are 

concerns

Nitrogen (N) and Phosphorus (P) – primary nutrients that in excessive amounts pollute surface water

1997 – Clean Water Action Plan

• EPA identified nutrients as significant national problem contributing to water pollution

nutrients: nitrogen

Nitrate – primary ion of interest in watershed management

• Readily mobile

Sources of excess nitrate – septic systems, animal feed lots, agricultural fertilizers, manure, industrial waste, sanitary landfills, garbage dumps

nutrients: phosphorus

Phosphorus attaches to soil particles

• Moves into surface water from runoff

Sources of phosphorus – agricultural fertilizers, manure, organic wastes in sewage and industrial effluent

heavy metals: issues is that they occur

naturally

Concentrated due to human activities

Multitude of impacts, both acute and chronic exposures

• Depending on the element

Sources – mining, industrial waste, vehicle emissions, fertilizers, batteries, paint, aging water supply infrastructure

examples of heavy metals

lead

mercury

arsenic

chromium

cadmium

Others – manganese, cobalt, nickel, copper, zinc, selenium, silver, tin, antimony, thallium

heavy metal: lead

Additive to gasoline – high levels in soil near roads

Believed to be 2-3X pre-industrial era

Neurotoxin

heavy metal: mercury

Coal and gas-fired electric generation

Neurotoxin

heavy metal: arsenic

carcinogenic

heavy metal: chromium

carcinogenic

heavy metals: cadmium

causes degenerative bone disease

pharmaceuticals: examples

Prescription drugs, over-the-counter drugs

pharmaceuticals: impacts

Antibiotics -> resistant bacteria

Generally designed to be biologically active in living organisms

• Problems when released to the environment

pharmaceuticals: entry into the enironment

Excreted in urine

Water treatment not equipped to treat all possible chemicals

Dumping of unused materials in either wastewater or solid waste

Manufacturing processes

microplastics

Emerging issue

Prevalence

• Found in virtually every ecosystem type

  • Aerial, terrestrial, aquatic

  • Found throughout food chains

• For us

  • Air we breathe

  • Food we eat

  • Water we drink

  • Virtually all human tissues and organs

microplastics: scale of the problem

Annual releases

• 10-40 million metric tons

• Expected to double by 2040

sources of microplastics

Breakdown of larger plastic items

• Plastic water bottles

• Synthetic textiles (polyester, nylon)

• Tires

• Paint

• Plastic bags

Intentionally added to cosmetics and cleaners

Use of sewage sludge as fertilizer

microplastics: human consumption

78,000 to 211,000 particles annually (per person) via food, water, and breathing

microplastics: in the body

Tissues and organs

• Blood

• Lungs

• Liver

• Bones

• Kidneys

• Saliva

• Placenta

Brain (7-10X more than other tissues)

microplastics: known health issues

Increased likelihood of

• Cardiovascular disease

• Respiratory diseases

• Reproductive issues

• Stroke

• Risk of dementia – not fully demonstrated, yet

• Premature birth

• Cancer

• Osteoporosis

• Disrupted gut biome

• Endocrine Disrupting Chemicals (EDC) exposure (and all that comes with it)

• Pathogens (riding on microplastic particles)

microplastics: environmental effects

Not fully known, obviously

Blue Whales – ingest 10 million daily

Known effects (variety of organisms, mostly aquatic)

• Bioaccumulation and biomagnification

• Reduced food intake

• Stunted growth

• Behavioral changes

• Lower reproductive success

• Reduced energy levels

• Alter gene expression

• Cellular/DNA damage

how do we avoid microplastics

Drink filtered tap water instead of bottled water

• Reduces intake by 90%

Avoid clothes with synthetic materials

• Polyester, nylon, etc.

Cut back on seafood and alcohol

Avoid single use plastics

Use glass containers to store food

Don’t heat in microwaves or ovens

Limit canned food consumption

Wood or bamboo cutting board

list the different characteristics of water quality: physical

1. Suspended Sediments

2. Thermal Pollution

3. Dissolved Oxygen

4. Biological Oxygen Demand

5. pH

6. Turbidity

total sediment load =

suspended sediment + bed load

suspended sediments: impact on water quality

Restrict sunlight from reaching photosynthetic plants

Smother benthic communities and cover gravels that are important spawning habitat for fish

Carry nutrients and heavy metals

water quality: thermal pollution

Act of altering the temperature of a natural water body

Temperature extremes can control the survival of flora and fauna

Increase in temperature

• Increase in biological activity

• Increase in dissolved oxygen demand

EX. Replacement of cold-water trout with warm water bass or walleye

water quality: Dissolved Oxygen

DO is essential for the survival of all aquatic organisms

Level is related to water temperature

Can fluctuate rapidly in time and space

Biologically

• One of most important water quality characteristics

water quality: Biological Oxygen Demand (BOD)

BOD is quantity of oxygen used by microorganisms (i.e. aerobic bacteria) in oxidation of organic matter

Oxygen consumed in decomposition robs other aquatic organisms of oxygen needed for survival

Organisms more tolerant of lower DO may replace a diversity of more sensitive organisms

water quality: pH

Measure of how acidic/basic water is

• Neutral is 7.0

Alkalinity refers to capability to neutralize acid

Most aquatic organisms become stressed outside pH range of 5.5 to 8.5

Determines solubility and biological availability of chemical constituents and heavy metals

Acidity can aggravate toxic contamination problems

Water Quality: Turbidity

Indicator of property of water that causes light to be refracted or absorbed

Low turbidity => deeper penetration of light

High turbidity => increased temperature => reduces DO

Sources – soil erosion, waste discharge, urban runoff, eroding streambanks, large numbers of bottom feeders, excessive algal growth

Water quality: biological

Waterborne Bacteria and Protozoa

biological: Bacteria and Protozoa

Cause illness in humans, livestock, and wildlife

• E. coli

  • Indicator of suitability for drinking and recreational use

• Giardia and Cryptosporidium

  • Protozoa carried by animals (rodents, deer, elk, and livestock)

Giardia

Causes Giardiasis

Not fatal, but great discomfort

Contaminated by feces from infected animals

• Feces may contain a hundred million cysts

• As few as 10 to cause infection

How to treat for Giardia (options ranked)

• Boil

• Filter

• Disinfect