EUTROPHICATION

INTRODUCTIONEutrophication is a natural phenomenon in which the water becomes green and degraded. It is a natural process which became a problem because of human activities. Human activities increases the rate of eutrophication in water bodies.

CAUSES (POINT SOURCES)Wastewater effluent (municipal and

industrial)Runoff and leachate from waste disposal

systemsRunoff and infiltration from animal feedlotsRunoff from mines, oil fields, unsewered

industrial sitesOverflows of combined storm and sanitary

sewersRunoff from construction sites less than

20,000 m² (220,000 ft²)Untreated sewage

CAUSES (NON-POINT SOURCES)Runoff from agriculture/irrigationRunoff from pasture and rangeUrban runoff from unsewered areasSeptic tank leachateRunoff from construction sites >20,000 m²Runoff from abandoned minesAtmospheric deposition over a water surfaceOther land activities generating

contaminants

MECHANISM

EFFECTSReduce quality of waterSubmerged aquatic vegetationOxygen depletionGrowth of Aquatic Plants Species ChangesEnhanced Internal Recycling of

Nutrients Elevated Nitrate ConcentrationsIncreased Incidence of Water-related

DiseasesIncreased Fish Yields

IMPACTSDecreased biodiversity

New species invasion

Toxicity

MITIGATIONRIPARIAN BUFFER ZONESPREVENTION POLICIES1. Technologies2. Waste dispose technology3. Public participation4. Economic instruments NITROGEN TESTING AND MODELLING ORGANIC FARMING