Instrument Information Indicator Organisms An organism which indicates the presence of contamination and the potential presence of other (usually pathogenic) organisms. Biochemical Oxygen Demand Dissloved Oxygen Chlorophyll Phytoplankton Other Nutrients Synthetic Organic Compounds Pesticides Carbon Organic Carbon, Indicators InOrganic Carbon CO2 Major Weathering Products Soil Sediment Water Micronutrients Macronutrients Nitrogen Ammonia Nitrogen Phosphorus Carbon as Nutrient Hydrogen Ion Activity Alkalinity Noble Gases Forms of Water Radioactive Isotopes Hardness Metals Heavy Metals A metal whose specific gravity is approximately 5.0 or higher. Light Metals A metal whose specific gravity is approximately 5.0 or less. Chromium Aluminum Priority Pollutants Chemical designated by the EPA as having high priority because of its toxicity or potential to cause cancer or mutations. Other Solids Dissolved Solids Suspended Solids Volatile Solids Conductivity Soil Parameters Transparency