Laboratory

Public wastewater systems must demonstrate that their wastewater effluent being discharge meets environmental and health based standards by periodically monitoring for the presence of specific contaminants.

Approved analytical methods must be used when analyzing wastewater samples to meet federal monitoring requirements or to demonstrate compliance with regulations. The EPA reviews and approves methods that can be used. These methods are then adopted by the State of Wisconsin. Annual proficiency samples must be analyzed by the laboratory. Determining the correct concentration of compounds in the samples is required for a laboratory to be categorized as a registered or certified laboratory by the State.

The Racine Wastewater Utility has a laboratory which analyzes wastewater and solids samples using state-of-the-art equipment. The data which is generated from this testing is used to monitor the effectiveness of the treatment plant, ensure compliance with the City of Racine Sewer Use Ordinance and evaluate the health of Lake Michigan.

The operation of the complex plant processes requires monitoring and testing on a continuous basis. The plant laboratory is used for testing the quality of the water as it passes through each plant process and the sludge quality as is passes through the solids handling process. Laboratory data is also used to assure compliance with stringent regulatory requirements for discharge of the treated water and recycling of biosolids.

The laboratory of the Racine Wastewater Utility is certified by the State of Wisconsin and follows all guidelines as required by the Wisconsin Laboratory Certification & Registration Program. Our lab has received accreditation for the following:

• Ammonia as Nitrogen
• Biochemical Oxygen Demand
• Cyanide
• Hardness
• Kjeldahl Nitrogen
• Phosphorus
• Total Solids
• Total Suspended Solids
• Metals: arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, molybdenum, nickel, potassium, selenium, silver and zinc

BOD

Biochemical oxygen demand measures the amount of oxygen required by aerobic microorganisms to decompose the organic matter in a sample of water, such as that polluted by sewage. It is used as a measure of the degree of water pollution. This is the measure of how much oxygen in the water will be required to finish digesting the organic material left in the effluent. Ideally, the BOD would be zero.

Biochemical Oxygen Demand (BOD) is one of the most common measures of pollutant organic material in water. BOD indicates the amount of organic matter present in water. Therefore, a low BOD is an indicator of good quality water, while a high BOD indicates polluted water. Dissolved oxygen (DO) is consumed by bacteria when large amounts of organic matter from sewage or other discharges are present in the water. DO is the actual amount of oxygen available in dissolved form in the water. When the DO drops below a certain level, the life forms in that water are unable to continue at a normal rate. The decrease in the oxygen supply in the water has a negative effect on the fish and other aquatic life. Fish kills and an invasion and growth of certain types of aquatic weeds can cause dramatic changes in a stream or other body of water. Energy is derived from the oxidation process. BOD specifies the strength of sewage. In sewage treatment, to say that the BOD has been reduced from 500 to 50 indicates that there has been a 90 percent reduction.

CYANIDE

Cyanide is an industrial waste, typically used in metal plating operations. Any measureable cyanide in the wastewater would be from an untreated industrial source. Industries that may be using cyanide are in the pretreatment program, and subject to stringent discharge limits.

HARDNESS

Hardness is a measurement of calcium and magnesium. Hardness in measured in the wastewater plant discharge on a quarterly basis.

NITROGEN

Nitrogen is an essential ingredient in the formation of proteins for cell growth. From complex organisms like animals to the simple bacteria used to treat wastes in an activated sludge treatment facility, every living thing needs some form of nitrogen to survive.

But too much nitrogen freely available in the environment can be a bad thing. Excess nitrogen discharged into our waterways can contribute to the gradual change of water bodies into marshes, meadows, and forests. It can also contribute to massive algae blooms leading to oxygen depletion in water and its associated problems. Certain forms of nitrogen can cause specific problems too. Ammonia is toxic to fish, and nitrates at high enough dosages in the drinking water cause illness in infants.

In the wastewater field we are concerned with several forms of nitrogen: ammonia, organic, nitrate, and nitrite. Under the right conditions, each of these forms is biologically convertible to one of the other forms. This creates certain challenges in the treatment of nitrogen in wastewater. Because of these challenges, it is important to properly collect, preserve, and analyze samples for the specific forms of nitrogen so that the appropriate treatment of these wastes can be made.

PHOSPHORUS

Total Phosphorus is the total concentration of phosphorus found in the wastewater.

Phosphorus is a nutrient and acts as a fertilizer, increasing the growth of plant life. Phosphorus comes from several sources: human wastes, animal wastes, industrial wastes, and human disturbance of the land and its vegetation. Sewage from wastewater treatment plants and septic tanks is one source of phosphorus in rivers and lakes.

Phosphorus can be removed from wastewater by various means. The Racine Wastewater Treatment Plant removes phosphorus with ferric chloride, greatly reducing the amount of phosphorus discharged to the lake.

TSS

Total Suspended Solids is a water quality measurement usually abbreviated as TSS. It is listed as a conventional pollutant in the U.S. Clean Water Act. It is a measure of the amount of small, particulate solid pollutants that are suspended in wastewater after treatment. Ideally, suspended solids would be zero.

These particles suspended in water will not pass through a filter. Suspended solids are present in sanitary wastewater and many types of industrial wastewater. TSS can include a wide variety of organic and inorganic material, such as silt, decaying plant and animal matter, industrial wastes, and sewage.

TS

Total Solids is a measurement of the inorganic and organic substances in a sample. Total solids testing is used for plant operation and control, to control chemical addition, and to measure the amount of solid material being hauled from the plant.

METALS

Low levels of various metals can be found in the wastewater entering the treatment plant. Metals in the influent are primarily contributed by industrial discharge. The pretreatment program which was started in 1984 resulted in a dramatic decrease in the amount of metals discharged to the treatment plant. Most metals settle during the wastewater treatment process and are removed with the biosolids. Since biosolids are often spread on farm fields, low metal concentrations are important. The Wisconsin DNR has established a low level of metals in biosolids that is called High Quality Standard biosolids. The biosolids from the Racine Wastewater Treatment Plant meet all of the concentration limits needed to be considered High Quality Stansdard, and has earned that rating since 1985.