Hydrologists

Hydrologists study water and the water cycle. They study the movement, distribution, and other properties of water, and they analyze how these influence the surrounding environment. They use their expertise to solve problems concerning water quality and availability, for example.

Hydrologists typically do the following:

  • Measure the properties of bodies of water, such as volume and stream flow
  • Collect water and soil samples to test for certain properties, such as levels of pollution
  • Apply research findings to help minimize the environmental impacts of pollution, erosion, and other problems
  • Research ways to improve water conservation and preservation
  • Use computer models to forecast future water supplies, the spread of pollution, and other events
  • Evaluate the feasibility of water-related projects, such as hydroelectric power plants, irrigation systems, and waste treatment facilities
  • Prepare written reports and presentations of their findings

Hydrologists use remote sensing equipment to collect data. They or technicians whom they supervise usually install and maintain this equipment.

They also use sophisticated computer programs to analyze and model data. They use sophisticated laboratory equipment to analyze chemical samples collected in the field.

Hydrologists work closely with engineers, scientists, and public officials to study and manage the water supply. For example, they work with policy makers to develop water conservation plans and with biologists to monitor marine wildlife.

Most hydrologists specialize in a specific water source or a certain aspect of the water cycle, such as the evaporation of water from lakes and streams. Some of the most common specialties are:

Groundwater hydrologists study the water below the Earth's surface. They decide the best locations for wells and the amount of water that should be pumped. They are often consulted about the best places to build waste disposal sites to ensure that the waste does not contaminate the groundwater.

Hydrometeorologists study the relationship between surface waters and water in the atmosphere. For example, to predict and prepare for droughts, they study how much rain or snow a particular area gets and how that evaporates.

Surface water hydrologists study water from above ground sources such as streams, lakes, and snow packs. They may predict future water levels and usage to help reservoir managers decide when to release or store water. They also produce flood forecasts and help develop flood management plans.

Some people with a hydrology background become professors or teachers. For more information, see the profile on postsecondary teachers.


Painters, Construction and Maintenance

Painters apply paint, stain, and coatings to walls, buildings, bridges, and other structures.

Painters typically do the following:

  • Cover floors and furniture with drop-cloths and tarps to protect surfaces
  • Remove fixtures such as pictures, door knobs, or electric switch covers
  • Put up scaffolding and set up ladders
  • Fill holes and cracks with caulk, putty, plaster, or other compounds
  • Prepare surfaces by scraping, wire brushing, or sanding to a smooth finish
  • Calculate the area to be painted and the amount of paint needed
  • Apply primers or sealers so the paint will adhere
  • Choose and mix paints and stains to reach desired color and appearance
  • Apply paint or other finishes using hand brushes, rollers, or sprayers

Applying paint to interior walls makes surfaces attractive and vibrant. In addition, paints and other sealers protect exterior surfaces from erosion caused by exposure to the weather.

Because there are several ways to apply paint, workers must be able to choose the proper tool for each job, such as the correct roller, power sprayer, and the right size brush. Choosing the right tool typically depends on the surface to be covered and the characteristics of the finish.

A few painters--mainly industrial--must use special safety equipment. For example, painting in confined spaces such as the inside of a large storage tank, requires workers to wear self-contained suits to avoid inhaling toxic fumes. When painting bridges, tall buildings, or oil rigs, painters may work from scaffolding, bosun's chairs, and harnesses to reach work areas.

The following are examples of types of painters:  

Construction painters apply paints, stains, and coatings to interior and exterior walls, new buildings, and other structural surfaces.

Maintenance painters remove old finishes and apply paints, stains, and coatings later in a structure's life. Some painters specialize in painting or coating industrial structures, such as bridges and oil rigs, to prevent corrosion.

Artisan painters specialize in creating distinct finishes by using one of many decorative techniques. One technique is adding glaze for added depth and texture. Other common techniques may include sponging, distressing, rag-rolling, color blocking, and faux finishes. 

Painting and coating workers apply materials to manufactured products, such as furniture, toys and pottery, as well as transportation equipment including trucks, buses, boats, and airplanes. For more information about these painters, see the profile on painting and coating workers.


Heating, Air Conditioning, and Refrigeration Mechanics and Installers

Heating, air conditioning, and refrigeration mechanics and installers--often referred to as HVACR technicians--work on heating, ventilation, cooling, and refrigeration systems that control the air quality in many types of buildings.

Heating, air conditioning, and refrigeration mechanics and installers typically do the following:

  • Travel to worksites
  • Follow blueprints or other design specifications to install or repair HVACR systems
  • Connect systems to fuel and water supply lines, air ducts, and other components
  • Install electrical wiring and controls and test for proper operation
  • Inspect and maintain customers' HVACR systems
  • Test individual components to determine necessary repairs
  • Repair or replace worn or defective parts

Heating and air conditioning systems control the temperature, humidity, and overall air quality in homes, businesses, and other buildings. By providing a climate controlled environment, refrigeration systems make it possible to store and transport food, medicine, and other perishable items.

Although trained to do all three, HVACR technicians sometimes work strictly with heating, air conditioning, or refrigeration systems. They also may specialize in certain types of HVACR equipment, such as water-based heating systems, solar panels, or commercial refrigeration.

Depending on the task, HVACR technicians use many different tools. For example, they often use screwdrivers, wrenches, pipe cutters and other basic handtools when installing systems. To test or install complex system components, technicians may use more sophisticated tools, such as carbon monoxide testers, voltmeters, combustion analyzers, and acetylene torches.

When working on air conditioning and refrigeration systems, technicians must follow government regulations regarding the conservation, recovery, and recycling of refrigerants. This often entails proper handling and disposal of fluids.  

Some HVACR technicians sell service contracts to their clients, providing regular maintenance of heating and cooling systems.

Other craft workers sometimes help install or repair cooling and heating systems. For example, on a large air conditioning installation job, especially one in which workers are covered by union contracts, ductwork might be done by sheet metal workers and duct installers, or electrical work by electricians. In addition, home appliance repairers usually service window air conditioners and household refrigerators. For more information on these occupations, see the profiles on sheet metal workers, electricians, or home appliance repairers.


Roofers

Roofers repair and install the roofs of buildings using a variety of materials, including shingles, asphalt, and metal.

Roofers typically do the following:

  • Inspect problem roofs to determine the best way to repair them
  • Measure roof to calculate the quantities of materials needed
  • Replace damaged or rotting joists or plywood
  • Install vapor barriers or layers of insulation
  • Install shingles, asphalt, metal, or other materials to make the roof watertight
  • Align roofing materials with edges of the roof
  • Cut roofing materials to fit angles formed by walls, vents, or intersecting roof surfaces
  • Cover exposed nail or screw heads with roofing cement or caulk to prevent leakage

Properly installed roofs keep water from leaking into buildings and damaging the interior, equipment, or furnishings.

There are two basic types of roofs, low-slope and steep-slope:

  • Low-slope: About two-thirds of all roofs are low-slope. Most commercial, industrial, and apartment buildings have low-slope roofs. Low-slope roofs rise 4 inches or less per horizontal foot and are installed in layers.

    For low-slope roofs, roofers typically use several layers of roofing materials or felt membranes stuck together with hot bitumen (a tar-like substance). They glaze the top layer to make a smooth surface or embed gravel in the hot bitumen to make a rough surface.

    An increasing number of low-slope roofs are covered with a single-ply membrane of waterproof rubber or thermoplastic compounds.
  • Steep-slope: Most of the remaining roofs are steep-slope. Most single-family houses have steep-slope roofs. Steep-slope roofs rise more than 4 inches per horizontal foot.

    For steep-slope roofs, roofers typically use asphalt shingles, which often cost less than other coverings. On steep-slope roofs, some roofers also install tile, solar shingles, fiberglass shingles, metal shingles, or shakes (rough wooden shingles).

    To apply shingles, roofers first lay, cut, and tack 3-foot strips of roofing over the entire roof. Then, starting from the bottom edge, they nail overlapping rows of shingles to the roof.

A small but increasing number of buildings now have “green” roofs that incorporate landscape roofing systems. A landscape roofing system typically begins with a single or multiple waterproof layers. After that layer is proven to be leak free, roofers put a root barrier over it, and, finally, layers of soil, in which vegetation is planted. Roofers must ensure that the roof is watertight and can endure the weight and water needs of the plants.


Environmental Engineers

Environmental engineers use the principles of engineering, soil science, biology, and chemistry to develop solutions to environmental problems. They are involved in efforts to improve recycling, waste disposal, public health, and control of water and air pollution. They also address global issues, such as safe drinking water, climate change, and sustainability.

Environmental engineers typically do the following:

  • Prepare, review, and update environmental investigation reports
  • Design projects leading to environmental protection, such as water reclamation facilities, air pollution control systems, and operations that convert waste to energy
  • Obtain, update, and maintain plans, permits, and standard operating procedures
  • Provide technical support for environmental remediation projects and legal actions
  • Analyze scientific data and do quality-control checks
  • Monitor progress of environmental improvement programs
  • Inspect industrial and municipal facilities and programs to ensure compliance with environmental regulations
  • Advise corporations and government agencies about procedures for cleaning up contaminated sites

Environmental engineers conduct hazardous-waste management studies in which they evaluate the significance of the hazard and advise on treating and containing it. They also design municipal water supply and industrial wastewater treatment systems and research the environmental impact of proposed construction projects. Environmental engineers in government develop regulations to prevent mishaps.

Some environmental engineers study ways to minimize the effects of acid rain, global warming, automobile emissions, and ozone depletion. They also collaborate with environmental scientists, planners, hazardous waste technicians, engineers, and other specialists, such as experts in law and business, to address environmental problems and sustainability. For more information, see the job profiles on environmental scientists and specialists, hazardous materials removal workers, lawyers, and urban and regional planners.


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