Urbanization and Water

Urbanization is the process of a population shifting from rural to urban areas. The world is currently undergoing the largest shift of population placement and urban growth in history. More than half of the world's population now lives in towns and cities, and it predicted that by 2050 about 65% of the developing world and 86% of the developed world will be urbanized. The United Nations predicts that nearly all global population growth between 2015 and 2030 will reside in cities. Much of this urbanization will occur in previously undeveloped places such as Africa and Asia.

Urbanization ripples into a range of topics, including geography, sociology, economics, urban planning, and public health. It brings huge social, economic, and environmental changes. While urbanization has provided us with many opportunities for sustainable living and development, more often than not, we have fallen through on these opportunities and only created more problems.

Water quality has been largely affected by urban growth. Some water quality issues that relate to urban growth include:

Population Growth

The more people move into an area, the more an area must be developed and the more facilities must be built to support this population. These facilities include housing developments, roads, shopping areas, and commercial and industrial facilities, all of which require water to build and maintain. All of these facilities require plumbing and running water. Supplying more people with water puts stress on the water quality and supply. For example, Atlanta, Ga., one of the fastest growing metropolitan areas in the world, had to restrict development in the late 1980s because water-supply systems were not in place to handle the rapidly expanding growth in northern Atlanta. For much of 1997, the city was fined daily for releasing water with high levels of bacteria. When you have a booming population, it becomes difficult to keep up with the necessary facilities to keep water safe and uncontaminated. 

Erosion and Sedimentation
Development causes an increase in erosion because it removes the roots that hold soils in place.

Nitrogen

Nitrogen can be introduced through sewage and fertilizers. Heavy rains generate runoff containing these materials and allowing them to leach into nearby streams and lakes. Wastewater treatment facilities do not always remove excess nitrogen, which can lead to excess levels of nitrogen in surface or groundwater. Excess nutrients can cause eutrophication in aquatic ecosystems, which is a reduction in dissolved oxygen in water caused by an increase of organic nutrients. Nitrate can get into water as a result of runoff from fertilizers and also from the atmosphere. The atmosphere carries nitrogen-containing compounds derived from automobiles and other fossil-fuel burning sources. More than 3 million tons of nitrogen are deposited into the atmosphere each year by the United States, mainly derived from the combustion of fossil fuels. 

Phosphorous
Phosphorous can be found in agricultural fertilizers, manure, sewage and industrial wastes. Too much phosphorous in aquatic ecosystems can cause eutrophication. Soil erosion is a major contributor to this problem. Industries and automobiles that burn fossil fuels are a major player in the phosphorous cycle imbalance. 

Urban Runoff
Development causes increased erosion and sedimentation. When you pave a piece of land, that land becomes impermeable. This means that rainwater cannot reach the ground underneath the pavement, therefore it runs on top of the pavement until it reaches a soil it can absorb into. While the water runs along the pavement, it picks up pollutants along the way, including gasoline, plastics, and rubber. When the water finally reaches a soil or a river, it is carrying a whole slew of pollutants.

Sewage Overflows
There are three types of sewer systems:

1. Storm sewers carry storm runoff from streets, parking lots, and roofs through pipes and ditches, and eventually into streams.

1. Sanitary sewers carry raw sewage from homes and businesses to waste water-treatment facilities.

1. Combined sewers carry a combination of raw sewage and storm water runoff.

There are currently many adverse health affects to urbanization, but it doesn't have to look like this. With proper and sustainable planning, we can transform what the urban area looks like and what it means for the rest of our environment.

Blockages, inadequate carrying capacity, leaking pipes, and power outages at pumping stations often lead to sewage overflows into nearby stream. A rapid increase in population can leave these systems old, dirty, outdated, and more likely to cause problems. 

Waterborne Pathogens

Waterborne pathogens are disease-causing bacteria, viruses, and protozoans that are transmitted to people when they consume untreated or inadequately treated water. Cities routinely monitor the water supply to assure people are safe from waterborne pathogens, but with a rapid increase in a city's population, keeping up can be difficult. 

This picture shows a warning sign that has been put up alongside a stream near downtown Atlanta, Ga. Overflow of sewage has caused high bacteria levels in this stream. Urban runoff, sewage overflows, and waterborne pathogens are all very closely related when it comes to the quality of water in urban areas. 

Pesticides

Pesticides are heavily used in big agriculture, and we see a huge increase in the amount of pesticides used to grow our food since people stopped growing their own. In urban areas, the main use of pesticides is for residential and commercial uses (lawns, landscaping, etc). when a storm hits, these chemicals run off yards and into streams where they harm aquatic life and contaminate drinking water. 

Sources: 
The USGS Water Science School
UN Water
Global Water Partnership

Embedded Water

Embedded water is also known as virtual water, and it describes the concept of the hidden flow of water that exists within the production and transportation of food, goods, and services. Water is hidden in beer, burgers, clothing, cars, homes, and even electricity. Water is used to produce all of these things, and it is present inside of these things, but we do not usually take this water into account when we think about the resources it takes to produce the things we use and eat on a daily basis. Embedded water is water used to produce food and non-food products. For example, it takes about 1100 drops of water to produce one drop of coffee. It takes 136 drops of water to produce one drop of tea. 

Most of the water we consume is in our food, about 65% of it. We eat 3496 meters of water everyday.  A tomato has 13 litre of water embedded; an apple as about 70 litres; a pint of beer about 170 litres; a glass of milk 200 litres; and a hamburger about 2400 litres. Much of this water comes from the large scale systems that are used to produce and process this food, especially when discussing animal products such as dairy and meat. Cooling and processing systems require large amounts of water. Large scale agriculture also uses and wastes a large amount of water in the growing of produce and the feeding of animals. For example, 200 kilos of beef takes on average 3 years to 'grow.' During this three years, the animal will consume nearly 1300 kg of grains and 7200 kg of roughages, the production of which requires over 3 million liters of water. The cow will also drink 24,000 liters of water per year. There will also be 7000 liters used to service the farmhouse and slaughtering processes. This all means that to produce 1 kg of beef, we need 15,400 liters of water.  

Our domestic consumption is about 137 litres per day, and it includes things such as bathing, cleaning, flushing the toilet, laundry, and cooking. This is the visible water use. There are two invisible pieces. The first invisible part is the water used for the production of industrial products such as paper, cotton, and clothes. This equals about 167 liters per day. The other invisible part of our consumption is associated with the production of our food, and that equals about 3496 litres per day. This means that 92% of the water we use is invisible to us on a daily basis. 

Most of the embedded water that we consume as a nation, about 70%, is imported from other nations in the form of imported goods and services. This importation of water is also referred to as virtual water trade. The term virtual water was coined by Professor Tony Allan, and the concept has helped us understand how much water is needed to produce the food and goods we need. When a country imports one tonne of wheat instead of producing it domestically, it is saving about 1,300 cubic meters of indegineous water. This 'saves' the country's water and allows it to be used elsewhere. The exporting country has exported 1,300 cubic meters of virtual water since the real water used to grow the wheat will no longer be available for other purposes domestically. 

For more information on embedded water and the virtual water trade and what you can do to help, click here

Also, here.

Sources and Health Effects of NOx and SOx

NOx
NOx is a term for a family of highly reactive gases, including nitric oxide and nitrogen dioxide. These gases are produced from the reaction of nitrogen and oxygen gases during combustion at high temperatures. These reactions are often the result of the burning of fossil fuels. NOx pollution is emitted from vehicle exhaust, electric utilities, industrial boilers, power plants, cement kilns, and turbines, among other sources. 

Increased NOx in the environment creates more ozone, which can effect both terrestrial and aquatic life. Excess nitrogen in the air causes excess nitrogen in bodies of water, which can lead to eutrophication, a process that occurs when a body of water has an increase in nutrients that leads to a reduction of the amount of oxygen in the water, potentially suffocating fish and other aquatic life. 

NOx is a strong oxidizer, and when present in the air it can lead to the formation of corrosive nitric acid, resulting in acid rain and acidic environments. This oxidizing property also makes it a key player in the atmospheric reactions that cause smog. NOx also reacts with common organic compounds to form a wide variety of toxic products, including nitrate radical, nitroarenes, and nitrosamines. Nitrous oxide is a greenhouse gas contributing to climate change. 

NOx in the air affects the human respiratory system. Side effects of NOx exposure include increased inflammation in the airways, worsened cough and wheezing, reduced lung function, increased asthma attacks,and increased risk of respiratory infection or disease.  The small particles cause damage to lung tissue in the deep sensitive parts of the lungs, and can cause or worsen respiratory disease, and aggravate existing heart disease.These health problems can lead to premature death. 

SOx
SOx refers to all sulphur oxides, the two major ones being sulphur dioxide (SO2) and sulphur trioxide (SO3). Sulfur dioxide is a very utilized resource in many industries. It is used for things such as chemical preparation, refining, pulp-making, solvent extraction, and the preparation and preservation of food. SO2 emissions can come from fossil-fuel burning industries like gas processing, oil sands production, goal combustion, ore refining, and chemical manufacturing.

Sulfur dioxide can come from natural sources as well, including volcanoes and hot springs. Marshes and other places where biological decay is taking place can also be a source of sulphur dioxide. These places emit hydrogen sulphide, a toxic gas that smells like rotten eggs. Hydrogen sulphide is oxidized when it combines with the oxygen in the air, producing sulphur dioxide. Sulpur trioxide is slowly formed when sulphur dioxide combines with oxygen in the air, and sulphur trioxide rapidly combines with water to produce sulphuric acid. 


Sulfur oxides are also a major player in acid rain and smog. SOx tend to irritate the throat and lungs more often than the deep tissue, but if small particles are present, they can reach the respiratory system. 

Effects on Candelaria concolor and Physica Millegrana
Lichens Candelaria concolor and Physica millegrana thrive when faced with N heavy environments, including N inputs from fertilizer application in agricultural areas or N emissions from power plants, vehicle exhaust, and other industries. They are both classified as a Nitrophiles. Physica millegrana is also classified as a Tolerant species, as it generally responds positively to most pollutants, including NOx and SOx. 

Candelaria concolor. Source

Sources:

Clean Air Strategic Alliance

EPA AirTrends Nitrogen Dioxide

Australian Government Department of the Environment

American Lung Association: Nitrogen Dioxide

Lichen Biomonitoring in NCR

The Clean Air Act and the Ohio State Implementation Plan

A State Implementation Plan, or SIP, is a detailed set of regulations, policies, and infrastructure that are put in place to help the state of Ohio attain and maintain the National Ambient Air Quality Standards (NAAQS) for the six criteria pollutants listed in the Clean Air Act. These six pollutants are: ozone, particular matter (PM2.5), nitrogen oxides, sulfur dioxide, lead and carbon monoxide. These pollutants are often very present in Ohio because of the amount of industry that has taken here historically and still takes place here. Ohio maintains attainment for PM2.5, nitrogen dioxide, and carbon monoxide, while it still aspires to attainment for ozone, sulfur dioxide, and lead.

The Clean Air Act requires the U.S. EPA to set national ambient air quality standards for pollutants considered harmful to public health and the environment. The CAA requires the EPA to review air quality standards every five years to ensure their continued monitoring and safety. The EPA monitors the air via air 198 air monitors at 120 monitoring sites. These sites gathers information on the levels of sulfur dioxide, lead, particulate matter, nitrogen dioxide, carbon monoxide, and ozone in the air. The data is then analyzed to determine if levels are compliant with air quality standards. When a monitor exceeds the standard more than three times in a three-year period, the area is determined to not meet the standard, and is classified as being in “nonattainment.” An area can redeem itself by meeting the standards for three years in a row. After three years of such data, the State can petition the EPA to reclassify it as being in attainment, and they have 18 months to do so, although the area is still not officially redesignated until the EPA provides an opportunity for public comment and then publishes the final action in the Federal Register.

The standards for each of the pollutants is the following: 

• Carbon Monoxide: 9 ppm over eight hours; 35 ppm in one hour. Ohio is in full attainment for CO.
• Lead: 0.15 micrograms per cubic meter over a three-month average; 1.5 micrograms per cubic meter over a quarterly average. There are three nonattainment areas, including parts of Logan, Fulton, and Cuyahoga counties, likely a result of emissions from industrial facilities. Ohio has obtained three years of data that is within the standard for Logan County, and submitted a redesignation request in October 2013. The EPA had 18 months to act on the request in order to redesignate the area.
• Nitrogen Dioxide: 53 ppb in 24 hours and 100 ppb in 1 hour. Ohio currently does not have any monitors that have recorded data out of attainment, so therefore is currently in full attainment, but the EPA is requiring states to add more NO2 monitors near roads, many scheduled for installation in early 2014, so it’s likely there are many new monitors now in operation. After three years of data is collected from these monitors, attainment/nonattainment classifications may need to be revised.
• Ozone: 75 ppb in 8 hours. The State of Ohio is not in full attainment.
• Particulate Matter (PM2.5): 35 µg per square meter in 24 hours. The State of Ohio is in full attainment.
• Sulfur Dioxide: 75 parts per billion in one hour. The State of Ohio is not in full attainment, likely due to emissions from industries.

 In my research, I noticed that while there are specific standards that are measured with precision, there lacks any actual planning for implementation within the SIP. I'm left with questions such as: 

• How are we going to minimize these pollutants in the air?
• What is causing these pollutants to be in the air, and how can we prevent it? 

Diagram explaining the deposition of Sulfur Dioxide and Nitrogen Dioxide caused by emissions from industries in Ohio. Source: USDA Forest Service

For more information:

National Ambient Air Quality Standards Attainment Status of The State of Ohio

PDF Fact Sheet: What Citizens Need to Know about National Ambient Air Quality Standards and Attainment