Water Pollution The Oceans are large but they

Water Pollution The Oceans are large, but they can’t continue to dilute everything we dump into them.

Objective �SWBAT describe water pollution, its source(s), the history of remediation, and effective treatments to mitigate or eliminate major and minor pollutants.

What is Water Pollution? �In your composition book, please describe what you perceive “water pollution” to be. �Take 5 minutes to do so, while I take attendance.

Water Pollution �Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or that makes water unusable for desired uses. �Some pollutants are dilution-dependent (problematic only when in high enough concentration) and others are dilution-independent (problematic in any concentration).

Clean Water Act �Look up the Clean Water Act. �Who introduced it in the Senate? When? �Describe it’s path through Congress. �Who was President when the bill made it through Congress? �What happened next?

Types of pollutants �Disease-causing agents – bacteria, viruses, protozoa, and parasitic worms. �Oxygen-demanding wastes – aerobic bacteria. �Water-soluble inorganic chemicals – acids, salts, toxic metals (lead, mercury). �Inorganic plant nutrients – nitrates and phosphates. �Organic chemicals – gasoline, oil, plastics, pesticides, cleaning solvents �Sediment – suspended matter �Heat – excess heat energy.

Examples

Sources �Point-source – discharged at specific locations. Pipes, ditches, and sewers that discharge into bodies of surface water. Typical of factory and municipal waste. �Nonpoint-source – cannot be traced to a specific discharge location. Fields and riverbanks. Typical of agricultural waste.

Objective �SWBAT describe water pollution, its source(s), the history of remediation, and effective treatments to mitigate or eliminate major and minor pollutants.

Eutrophication �Excess nutrients flow into a body of water and cause an algal bloom. �The increased turbidity (cloudiness) of the water results in sunlight not reaching submerged aquatic vegetation (SAV). �Oxygen levels drop (hypoxia) as a result. �If conditions continue, oxygen becomes depleted anoxia sets in. �As a result, a waterway is said to be “dead”, with little or no aquatic life remaining.

Case Study – Pfiesteria piscida �P. piscida is a dinoflagellate (Greek for “whirling whip”), which lives in brackish (mix of fresh and salt) water, photosynthesizes, and their numbers are kept in check due to seasonal temperature changes. �While there are typically autotrophic, they are said to be “opportunistic heterotrophs” in times of high nitrate levels. �In 1997, there was an outbreak of P. piscida in rivers on the Eastern Shore of Maryland. �As a result, there was a fish kill of approximately 3, 000 tons. �Additionally, P. piscida has been linked to neurological damage in humans handling infected fish.

What caused the problem? �Historically, corn has been the #1 agricultural product of Maryland (following tobacco being displaced). �For decades, the poultry ranchers and the corn farmers have cooperated in utilizing chicken manure, which is high in nitrogen content, as a fertilizer for corn plants, which requires a large amount of nitrogen. �In the last 2 decades, changes in tax laws and dropping corn prices have forced many corn farmers to sell their land. �Much of this land was bought by large industrial farm cooperatives. �These cooperatives are able to grow more corn per acre, so production was kept constant with less land. �Other land was sold to developers for housing subdivisions and shopping centers.

The problem (continued) �Chicken ranchers have developed new ways of warehousing larger herds of chickens in the same size buildings. �These warehouses typically crowd chickens into spaces little larger than their bodies. �The chickens are fed a high-protein diet, laced with antibiotics and steroids to keep them healthy and allow them to produce more meat. �The waste from these chickens is higher in nitrogen content than chickens of just 10 years ago. �In 2014, the Eastern Shore of Maryland produced 570 million chickens and 650 million pounds of chicken waste. �This waste needs to be dried prior to being spread on fields as fertilizer. Fresh manure will runoff quickly.

What can be done? �Chickens are now the #1 agricultural product in Maryland. �Large scale operations contribute mightily to political campaigns to ensure favorable treatment. �There currently exists no legislation stipulating exactly who is responsible for the drying of manure prior to being used as a fertilizer, or what rate of application is sustainable and will prevent nutrient runoff. �Legislate vs. Educate. Passing laws alone is not the answer, nor is just informing the farmers, ranchers, and public. There needs to be a balanced approach in order for meaningful change to occur.

Indoor Water Pollution �Witness what is happening in Flint, MI. �Lead solder, used to connect water supply pipes, have been leaching into the water. �The city of Flint had been adding anti-corrosive agents to the water, reducing the amount of lead leaching. �In 2013, in a cost-cutting measure, addition of the anti -corrosive agent was reduced, and then discontinued. �Multiple agencies raised awareness of the danger posed by the contaminated water. �To this day, the problem has not been corrected.