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Text 1 (2800)

Water Engineering

1. Memorise the following technical words:

aqueduct – акведук, наземный водопровод

dispose – удалять, сбрасывать, отводить (сточные воды)

lead [led] – свинец

meet standards – соответствовать (удовлетворять) стандартам

pollutant = contaminant – загрязняющее вещество, примесь, загрязнитель

potable – питьевой, годный для питья

sewer – канализационный коллектор, канализационная труба

supplier – поставщик

waste water – сточные воды

water body = body of water – водоем

water quality standards – стандарты качества питьевой воды

2. Study the meanings of the following misleading words:

technique – метод, прием

3. Read and translate:

Many of the great engineering achievements since earliest days have been associated with providing a reliable water supply and with disposing of wastewater. The Roman aqueducts that supplied Rome and other cities with drinking water between 300 BC and AD 300 are one example of this. The sewer system in London developed during the late 1800s is another example. Because of these engineering accomplishments, most people in the developed world have access to safe drinking water.

This section describes the relationship between engineering and water and the concept of water quality standards and how drinking water should meet these standards. It then describes the techniques engineers have developed to provide potable water and to treat wastewater so that it does not unduly pollute the environment.

Water Quality Standards

It is well known that the water people receive from the public water supply systems is treated. The treatment of water has to follow water quality standards. In the United States, the development of water quality standards began in the early twentieth century. Over time, these water quality standards have evolved and have become more rigorous. Laws and regulations such as the Clean Water Act govern water quality standards in the United States. The US Environmental Protection Agency (EPA) has the mission of protecting human health and the environment. The EPA has created water quality standards that define the goals for a body of water and specify its uses. They establish criteria to protect those water uses. They also establish requirements to protect water from pollutants.

Drinking Water

The quality of drinking water differs from one location to another. Quality is dependent on the condition of the water source and the treatment. Each local community water supplier is required to provide an annual report, sometimes known as a "consumer confidence report" to the public. This report usually provides information on the quality of the local drinking water, its source, and the contaminants found in the water.

Scientists report the contaminants in water in parts per million (ppm), parts per billion (ppb), and parts per trillion. When water contaminant measurements are reported in this manner, you may wonder: How can amounts of contaminants that seem so very small cause health problems? Scientific research has shown that, for example, lead concentrations as small as 15 ppb can be harmful to infants and children. The smell of petroleum products in water can be detected by humans even when the amount of petroleum in water is as low as 10 ppb.

It is very important to note that there is no such thing as naturally pure water. All water in nature contains some sort of impurities. Since water is a good solvent, as it flows through various layers of soil and over rocks, it dissolves minerals. These minerals in the water may get the taste (good or bad). However, if these minerals are above a certain level, they could be harmful.

Before the water is delivered to our homes, the water is treated. The treatment of drinking water that is most common is disinfection. Water suppliers add chlorine or another disinfectant to kill bacteria and germs in the water. This commonplace drinking water treatment is considered to be one of the most important scientific advancements of the twentieth century.

Notes:

consumer confidence report – зд. отчет, информирующий потребителей о состоянии поставляемой воды

4. Answer the questions:

1. What are water quality standards governed by? 2. What is the mission of the US Environmental Protection Agency? 3. Speak about the harmful effect of the slightest concentrations of some contaminants. 4. Why can’t pure water occur naturally? 5. Speak about the most common drinking water treatment, considered to be one of the important scientific advances of the 20^th century.

Text 2 (2400)

Water Treatment Basics

1. Memorise the following technical words:

adjust – регулировать, выверять, устанавливать

alum (aluminium potassium sulfate) – алюм, квасцы

coagulation – коагуляция

disinfectant – дезинфицирующее вещество

distribution – распределение, подача (воды)

drinking water treatment facility = water treatment plant

flock –хлопьевидная масса, флоккулированный осадок

flocculant – флоккулянт, хлопьеобразующий агент

layer – слой

sedimentation – осаждение, седиментация

sedimentation tank – отстойник, осадочный бассейн

storage – хранение, накопление, аккумулирование

storage tank – резервуар (для чистой воды)

sewage – сточные воды

valve –клапан, вентиль, задвижка

waste water treatment plant – завод по переработке сточных вод

water treatment plant – станция водоподготовки, водопроводная станция

2. Read and translate the text:

Municipalities must perform two types of water treatment: treatment of water before it is used for drinking and other purposes, and treatment of wastewater such as sewage so that it is safe to return to the environment. Typically, drinking water is treated based on the quality of the source water. Ground water, for instance, usually requires less treatment than surface water from a river or a lake. Thus, the quality of the water that enters your community water treatment plant determines how the water will be treated prior to distribution.

Wastewater includes sewage as well as water used in industrial and agricultural processes. It flows out of homes and neighborhoods through sewage pipes to a wastewater treatment plant. Here, the wastewater is treated to remove solids and contaminants. The treated wastewater may be re-used for irrigation and landscaping. The treated wastewater is also returned to streams, rivers, and oceans, which can also be a source of pollution.

Treatment plants for drinking water and for wastewater have equipment and processes to remove or destroy harmful materials and organisms. A treatment plant uses tanks and mechanical parts such as valves and pumps to move the water through the different processes. These processes are designed and managed by water engineers. Other engineering specialities, including mechanical and construction engineering, play a role in the construction and maintenance of water treatment plants.

Drinking Water Treatment

Water from rivers, lakes, and streams or ground water is pumped and transported to a drinking water treatment facility. Then the water is processed through various units to prepare the water for distribution to homes.

Coagulation. First, dirt and other particles must be removed from the water. Flocculants are chemicals such as alum (aluminum potassium sulfate) that cause the dirt and other particles to stick together; flocculants are added to the water, which creates larger particles called flock.

Sedimentation. As the water moves through the sedimentation tanks, the flock particles settle to the bottom of the tank. The clear water then flows to a filtration unit.

Filtration. Filtration removes small particles from the water by passing it through layers of sand, gravel and charcoal. The water then moves to disinfection before storage.

Disinfection. Water is disinfected with chlorine or other chemicals, called disinfectants, to kill any bacteria and other harmful organisms. The amount of disinfectants added to the water has to be carefully adjusted, because too much may be harmful to humans, but too little will not kill the harmful organisms.

Storage. After disinfection, the water is stored in storage tanks until it is needed for distribution to homes, businesses, and other water users.

3.Answer the questions:

1. How do treatment plants work? 2. What is coagulation? 3. What is the function of a filter? 4. Why is water disinfected?

Text 3 (3500)