Learning Center

Water and wastewater treatment is generally performed by physical, chemical or biological methods.  All treatment processes use some combination of these three methods.  Physical and chemical treatment are fairly straightforward, they use gravity settling, filtration and chemical reactions to remove impurities from the liquid to be treated. Biological treatment is somewhat more versatile, from a technical point of view.  Because treatment can be provided by a variety of processes and a wide ...

Facultative Bacteria Most of the bacteria that absorb the organic material in a wastewater treatment system are facultative in nature.  This means they are adaptable to survive and multiply in either anaerobic or aerobic conditions.  The nature of individual bacteria is dependent upon the environment in which they live.  Usually, facultative bacteria will be anaerobic unless there is some type of mechanical or biochemical process used to add oxygen to the wastewater.  When bacteria are i...

The American Decentralized Wastewater Association (ADWA) is an organization developed especially for companies that manufacture and market wastewater treatment devices certified as meeting the most recent version of ANSI/NSF Standard 40.  It is the mission of ADWA to nurture the onsite wastewater treatment industry by promoting rules, standards, training, and related activities consistent with contemporary public health and environmental protection standards.

Wastewater sampling is generally performed by one of two methods, grab sampling or composite sampling.  Grab sampling is just what it sounds like; all of the test material is collected at one time.  As such, a grab sample reflects performance only at the point in time that the sample was collected, and then only if the sample was properly collected.  Composite sampling consists of a collection of numerous individual discrete samples taken at regular intervals over a period of time, usually 24...

Two types of samples are collected and analyzed to determine the characteristics of treatment system effluent: grab samples and composite samples.  "A grab sample is one that is taken to represent one moment in time and is not mixed with any other samples.  A grab sample is sometimes called an individual or discrete sample and will only represent sample conditions at the exact moment it is collected."3  Grab samples are typically used for unstable parameters such as temperature, dissolved oxy...

A subsurface wastewater infiltration system (SWIS) is defined as "an underground system for dispersing and further treating pretreated wastewater.  The SWIS includes the distribution piping/units, any media installed around or below the distribution components, the biomat at the wastewater-soil interface, and the unsaturated soil below."¹  Out of necessity, leaching tile fields or other SWISs must sometimes be located in the proximity of seasonal or onsite groundwater.  This creates an operational problem as groundwater saturation will impede the normal aerobic function of a soil-based disposal system. 

Our factory training schools provide industry professionals a thorough understanding of water and wastewater treatment using Norweco products.  Each school is conducted at our factory in Norwalk, Ohio and is accredited for continuing education. Sixteen different curriculums are offered.  Teaching methods combine classroom style lectures with hands-on workshops to maximize the learning experience.  Upon satisfactory completion of a final exam, attendees are awarded hours of Continuing Educati...

Don’t drink water while studying… chemistry states that concentration decreases upon adding water. A paramecium and an amoeba are walking down the street. The amoeba asks “So, lacking any pseudopodia, how do you manage to get around? The paramecium replies “A cilia question I’ve never heard!” What did one cell say to his sister cell when she stepped on his toe? Mitosis Why are environmentalists bad at playing cards? They like to avoid the flush.

What does a wastewater treatment plant do? Treatment plants remove impurities contained in wastewater so that the treated wastewater can be safely returned to the environment. This same stabilization process occurs in nature to break down wastewater into its most basic components of carbon dioxide and water. Common methods of treatment include physical, biological and chemical treatment steps to stabilize the wastewater. Norweco wastewater treatment plants are designed to accelerate and control nature's process to insure proper treatment is provided.

These guidelines were derived from the Center for Disease Control (CDC) recommendations for workers handling wastewater. OSHA (Occupational Health and Safety Administration) and NIOSH (National Institute of Occupational Safety and Health) materials were also incorporated. This bulletin identifies basic hygiene guidelines, proper personal protective equipment (PPE), training on putting PPE on properly and taking PPE off properly, and information on vaccinations recommended for workers. It is imperative that...

Treating domestic wastewater from an individual home. Treating domestic wastewater from a group of homes, small businesses, a school or similar institution. Treating the wastewater from an industrial or manufacturing process such as a cooling tower, food or animal processing plant or any type of manufacturing process that generates wastewater. Treating domestic wastewater from a number of homes, businesses, schools or similar institutions along with small amounts of industrial wastewater from factories and industries.

Treating potable water for an individual home involves a flow range from 90 to 500 gallons per day. A small group of homes, businesses or a single institution such as a school, factory or food packaging facility can require treating several hundred to several million gallons per day of potable water. Treating potable water for municipal applications blends the requirements of residential, commercial and industrial users with a typical flow range from 100,000 to millions of gallons per day. Treating potable water up to 100,000 gallons per day in areas where clean drinking water is in short supply and power sources are limited presents numerous obstacles.

The disinfection of potable water and wastewater provides a degree of protection from contact with pathogenic organisms including those causing cholera, polio, typhoid, hepatitis and a number of other bacterial, viral and parasitic diseases.  Disinfection is a process where a significant percentage of pathogenic organisms are killed or controlled.  As an individual pathogenic organism can be difficult to detect in a large volume of water or wastewater, disinfection efficacy is most often measured ...

Flow equalization is the process of controlling hydraulic velocity, or flow rate, through a wastewater treatment system. The equalization of flow prevents short term, high volumes of incoming flow, called surges, from forcing solids and organic material out of the treatment process. Flow equalization also controls the flow through each stage of the treatment system, allowing adequate time for the physical, biological and chemical processes to take place. Published in 1974, the USEPA TECHNOLOGY TRANSFER REPORT states "The cyclic nature of wastewater flows in terms of volume and strength is well recognized."

National Environment Health Association The National Environmental Health Association is a 5,000 member professional society whose membership encompasses the public and the private sectors, as well as academia, the military and government agencies.  Founded to standardize the professional credentialing of health practitioners, NEHA states that its mission is "to advance the environmental health and protection professional for the purpose of providing a healthful environment for all."  NEHA's missi...

The National Academy of Sciences (NAS) was the first of the National Academies to be established. The 1863 session of Congress directed that "the Academy shall, whenever called upon by any department of the Government, investigate, examine, experiment, and report on any subject of science or art…" The first request to come before the newly formed NAS was from Salmon P. Chase, Secretary of the Treasury, who asked for a study on the "uniformity of weights, measures, and coins, considered in relation to domestic and international commerce."

According to the US National Academy of Sciences, humans are drastically changing the Earth’s climate. This theory is based on several factors, such as the sun’s lack of variations in recent decades. The sun, which is the primary source of energy driving the Earth’s climate system, has shown no increase in output while the Earth’s global surface temperature is believed to have increased. Various reports claim that this proves the sun’s lack of involvement in recent climate change. Climate changes, including natural ones, are disruptive. In the past they’ve led to the extinction of many species, population migrations, and pronounced changes in the land surface and ocean circulation.

The USEPA has provided clear and concise direction for the onsite wastewater treatment industry and regulatory community.  How to treat wastewater from areas not served by centralized municipal plants has received an increasing level of attention in recent years.  These areas use plants called Onsite or Decentralized treatment systems, because the waste is not transported to a central treatment facility.  Treatment often takes place on the site where the waste is generated.  The USEPA has reported that ...

Efforts to improve water quality continue to receive attention on a state and local basis.  Many of these evaluations take a watershed approach, which means looking at all the sources of water, and therefore all potential sources of pollution, for a given body of water or geographic area.  A recently published report, WATERSHED MANAGEMENT FOR POTABLE WATER SUPPLY, ASSESSING THE NEW YORK CITY STRATEGY, states "watersheds are nature's boundaries for surface water supplies.  Natural processes combined with ...

Local health authorities who administer local codes and guidelines are the backbone of public health protection in the United States.  As any local health department sanitarian will tell you, the real work of protecting the public health and the environment is done at the local level.  Like our democratic system of government, health authorities are subject to rules and regulations from other entities (e.g. federal and regional), but local sanitarians are the only ones really in position to have a direct ...

U.S. State Health Departments Alabama Department of Public Health RSA Tower P.O. Box 303017 Montgomery, AL 36130-3017 Telephone: (334) 206-5300 www.adph.org Alaska Department of Environmental Conservation Division of Environmental Health Drinking Water Program 555 Cordova Street Anchorage, AK 99501-2617 Telephone: (907) 269-7647 Fax: (907) 269-7655 www.dec.state.ak.us Arizona Department of Environmental Quality Water Quality Division 3033 N. Central Avenue Phoenix, AZ 85012 Telephone: (602) 207-2300 Fax: ...