Organic Matter:

Vegetable Plants, animals and human beings are the sources for origination of natural or synthetic organic compounds. Human excreta, paper products, detergents, cosmetics, food, agricultural products, wastes from commercial activities and wastes from industrial sources are organic in origin and considerable in quantity.

Organic compounds generated from the above sources are a combination of carbon, hydrogen, oxygen, nitrogen, sulfur and other trace elements. Organic compounds such as proteins, carbohydrates, and fats are degradable by organisms, however they can cause pollution.

Large concentration of degradable organics in wastewater is dangerous to lakes, streams, and oceans, because organisms consume dissolved oxygen in water to break down the wastes. This can reduce or deplete the supply of oxygen in the water needed by aquatic life, resulting in fish kills, increasing the odors, and overall deterioration of water quality.

Some organic compounds are more stable than others and cannot be quickly broken down by organisms. This poses an additional challenge for treatment. This is true with many synthetic organic compounds developed for agriculture and industry. Some of the synthetic organic compounds that belong to pesticides, herbicides, dyes, pigments, fried oils, and fried meats are toxic to humans, fish, and aquatic plants and often are disposed off improperly in drains or carried in storm-water. In receiving water bodies, they kill or contaminate fish, making them unfit to eat. They also can reduce the efficiency of the processes in treatment.

Gases:

What are the sources for gases in wastewater? Certain gases in wastewater can cause odors, affect treatment, so are potentially dangerous. Methane gas, for example, is a byproduct of anaerobic biological treatment and is highly combustible. Special precautions need to be taken near septic tanks, manholes, treatment plants, and other areas where wastewater gases can collect.

The gases hydrogen sulfide and ammonia can be toxic and pose asphyxiation hazards. Also, ammonia as a dissolved gas in wastewater is dangerous to fish. Both gases emit odors, which can be a serious nuisance. Unless effectively controlled or minimized by design and location, wastewater odors can affect the mental wellbeing and quality of life of residents. In some cases, odors can even lower property values and affect the local economy.

Oil & Grease:

Animal fat, vegetable and petroleum oils are not quickly broken down by bacteria and can cause permanent pollution in receiving environments. When large amounts of oils and greases are discharged to receiving waters from community systems, they may float to the surface and harden, causing aesthetically unpleasing conditions. The floating oils and grease decreases the oxygen transfer efficiency of water causing septic condition.

They also can bind with solid proteins, carbohydrate and other materials, causing foul odors, attracting flies, mosquitoes and other disease vectors.

Solids:

Solid materials in wastewater can consist of organic and/or inorganic materials. The solids must be significantly reduced by treatment or they would increase BOD when discharged to receiving waters and provide places for microorganisms to escape disinfection. They can also clog soil absorption fields in onsite systems.

Settleable solids - certain substances, such as sand, grit, and heavier organic and inorganic materials settle out from the rest of the wastewater stream during the preliminary stages of treatment. On the bottom of settling tanks and ponds, organic material makes up a biologically active layer of sludge that aids in treatment.

Suspended solids - materials that resist settling may remain suspended in wastewater. Suspended solids in wastewater must be treated, or they will clog soil absorption systems and reduce the effectiveness of disinfection systems.

Dissolved solids - small particles of certain wastewater materials can dissolve like salt in water. Microorganisms in wastewater consume some dissolved materials, but others, such as heavy metals, are difficult to remove by conventional treatment. Excessive amounts of dissolved solids in wastewater can have adverse effects on the environment.

Heavy metals:

Do you suspect heavy metals to be present in sewage? Municipal wastewater also contains a variety of potentially toxic elements such as arsenic, cadmium, chromium, copper, lead, mercury, zinc, etc. Even if toxic materials are not present in concentrations likely to affect humans, they might well be at phytotoxic levels, which would limit their agricultural use. However, from the health point of view, the greatest concern in the agricultural use of wastewater are the pathogenic micro and macro organisms.

Water that is polluted by humans, through residential, industrial or commercial activity, is called wastewater. These pollutants are often toxic substances and a hazard to the health of the people who consume or use it. It’s a hazard to the environment if left to sink into the ground. This gives rise to the need for treatment of wastewater, in order to remove the pollutants from water, and make it safe for consumption, and use. It must be treated even if merely let out in the environment, say to sink into the ground or to mix with sea water.

Why You Should Conserve Water?

Water conservation also indirectly helps in maintaining the water quality. Excessive water drawing (exceeding the water holding capacity of the soil) from ground sources allows ground water contamination from neighboring areas or sea. So, avoid unnecessary water drawing from ground sources. The volume of wastewater discharge can be reduced substantially through conservation of water.

This is a good idea for a number of reasons:

Significant reduction in wastewater flows also can save on personnel costs and can eliminate or postpone the need to upgrade or expand treatment facilities. It lowers sewer charges and taxes for homeowners. Water conservation also directly benefits homeowners with onsite systems. Simply by reducing water use, homeowners can extend the life of their systems for many years, prevent system failures, and minimize maintenance costs, potentially saving hundreds of dollars.

There are additional benefits such as lower monthly water bills, reduced amount of money that homeowners and communities spend for wastewater treatment, an increased efficiency of wastewater treatment plant, and savings on energy costs.

Nonresidential wastewater in small communities is generated by diverse sources such as offices, businesses, supermarkets, restaurants, schools, hospitals, farms, manufacturers and other commercial, industrial, and institutional entities. Storm-water is a nonresidential source and carries trash and other pollutants from streets, as well as pesticides and fertilizers from yards and fields.

Because of the different characteristics of nonresidential wastewater, communities need to assess each source individually or compare similar types of nonresidential sources to ensure that adequate treatment is provided.

What is wastewater?

The potable water becomes wastewater after it gets contaminated with natural or synthetic microbiological compounds that arise out of human activities, commercial and industrial sources. They may be accompanied with surface water, ground water and storm water. Wastewater is sewage, storm-water and water that has been used for various purposes around the community. Unless properly treated, wastewater can harm public health and the environment.

Most communities generate wastewater from both residential and non-residential sources.

Residential Wastewater or Household Wastewater

Residential wastewater is a combination of excreta, flush water and all types of wastewater generated from every room in a house. It is more commonly known as sewage and is much diluted. There are two types of domestic sewage: black-water or wastewater from toilets, and gray water, which is wastewater from all sources except toilets. Black-water and gray-water have different characteristics, but both contain pollutants and disease causing agents. In the U.S, sewage varies regionally and from home to home. These are based on factors such as the number and type of water-using fixtures and appliances used at homes and even their habits, such as the types of food they eat.

Non-Residential Wastewater or Industrial Wastewater

This could be places such as industrial complexes, factories, offices, restaurants, farms and hospitals.  Because of the different non-residential wastewater characteristics, communities need to assess each source individually to ensure that adequate treatment is provided. For example, laundries differ from many other industrial sources because they produce high volumes of wastewater containing lint fibers. Restaurants typically generate a lot of oil and grease. In addition, many industries produce wastewater high in chemical and biological pollutants that, can overburden onsite and community wastewater treatment systems.

Storm-water is a nonresidential source and carries trash and other pollutants from streets, as well as pesticides and fertilizers from yards and fields. Communities may require these types of nonresidential sources to provide preliminary treatment to protect community systems and public health.