Major Water Pollutants Leading Causes of Water Pollution

Major Water Pollutants

Leading Causes of Water Pollution n Most water pollution comes from: – Agriculture § Fertilizers, pesticides, bacteria, food wastes – Industrial Facilities § Sewage Treatment § Inorganic and organic chemicals – Mining § Sediment erosion, toxic chemical runoff/leaching

Agriculture n Nutrient Runoff – Pesticides – Fertilizers & Manuren Infectious Diseases n Sedimentation – Overgrazing n Chemical Pollution

Industrial n Organic & Inorganic Compounds n Heavy Metals n Thermal Pollution

World Wide Disposing sewage Drinking Same Water Source Bathing Washing

Wastewater n Two main systems: – Septic Systems – Sewage Treatment Plants

n Septic Tank Septic Systems – Large container holding wastewater from a household – Two parts: § Sludge – bottom layer of solids § Septage – middle liquid layer – More bacteria and nutrients n Leach Field – Septage distributed into soil

Sewage Treatment Plants n Urban areas

Testing for Water Pollutants n Temperature n Dissolved Oxygen n BOD n p. H n Nitrates n Phosphates n Turbidity n Indicator species n Coliform bacteria (E. coli)

Temperature n Range of Tolerance n Inverse relationship with Dissolved Oxygen (DO)

Dissolved Oxygen n Amount of oxygen available n Range 5 ppm and up n Things affecting DO: – Water movement higher DO – Decomposition lower DO – Temperature Inverse relationship

Biochemical Oxygen Demand (BOD) n Amount of oxygen a water system uses over a period of time at a specific temperature n Low BOD = Low Pollution n High BOD = High Pollution – High microbial activity leads to high BOD

p. H n Determines solubility of nutrients n Affects organism physiology n Species dependent

Nitrate & Phosphate n Limiting nutrients in aquatic ecosystems n Can result in extreme algal growth – Algal blooms – Red tide

Turbidity A measure of the degree to which the water loses its transparency due to the presence of suspended particulates. n Affects sunlight penetration n Affects predator/prey interactions n Affects gill function