DEWATERING

DEWATERING – WHAT IS IT AND WHY DO WE NEED IT?
Construction dewatering refers to the methods used to remove accumulated groundwater or surface water by pumping or thru evaporation.  When working on trenches, near a body of water, in areas with a high water table or an area filled because of rains and flooding it is important to understand proper methods for water removal.   Proper Dewatering protocol should be included in a site SWPPP (Stormwater Pollution Prevention Plan) for a construction site.  Methods may vary depending on municipality requirements, location of construction and proximity to waterways, lakes and streams.
   

IMPORTANT CONSIDERATIONS
When determining the type and scale of dewatering methods, some variables that need to be taken into consideration include the amount of water being relocated,  how fast it will travel (pump or gravity?), and the amount and type of impurities in the water.  Water that is pulled out of a ditch with a sump pump may have more sediment than water being removed from an area of a natural lake.  Either way, the water will typically need to be filtered as it is relocated to minimize the effects of erosion and sedimentation.   Water that is potentially polluted may need further treatment, such as using an oil and water separator to make sure that those impurities are not put back into natural waterways.

DEWATERING AND FILTRATION OPTIONS
In almost every case, dewatering will require some kind of filtration to remove impurities from the water as it is removed and directed to a draining area or waterway.   Some of these options include:

•  Filter Sock, filter bag or tube:  Filter Bags come in many shapes and sizes.   As the name states – these bags are a filter that hold in silt and impurities while allowing water to pass thru and drain away.

•  Dewatering Filter Pad – If needed, a dewatering pad allows for additional filtration beyond the sock or bag, using a combination of man-made and natural materials to clean the water.

•  Drainage Ditch with lining (to prevent further erosion) and FLOC Logs.   The Floc Logs are designed for use in flowing conditions for treating turbid water to remove suspended sediment


DEWATERING PRECAUTIONS
While the dewatering process is relatively simple, the reasons and methods are designed to protect our environment and require awareness and diligence to maintain the health of our natural waterways.   When dewatering an area, it is always best to be aware of the amount of water, where it is traveling and look for ways to prevent damage to the existing natural landscape.

•  Avoid overland routes that can cause further erosion
•  Choose the best place for the discharge keeping in mind amount of water and flow rate
•  Water leaving the construction site needs to be as clean as the water entering the site
•  All dewatering protocols need to be monitored regularly to avoid filtration failure

Proper Dewatering and SWPPP protocols are important steps in Construction Best Management Practices (BMPs) and should be taken seriously.   For more information contact our knowledgeable staff at 630-554-6655 or by email.

BUILDING UP....

In the past few years many schools have added to their educational offerings and begun to focus on Science, Technology and Math to encourage kids to learn the types of skills that are needed in our fast moving, technology enhanced lives.   In  today’s top career fields these are crucial skills to survive, however many educators are adding ‘Arts’ to the acronym because they realize that in all fields, creative solutions are the key to success.  Looking at Civil Engineering and Land Surveying it is easy to see where each of these educational components are needed to shape our youth into creative, problem solving professionals to tackle tomorrow’s needs.

CIVIL ENGINEERING AS A CAREER
Civil Engineering is the overall description that covers a wide range of Engineers who work on Public Projects such as buildings, roads, waterways, energy systems, ocean ports, railroads, and airports. Civil Engineering is broken down into subcategories with many different specialties.   But what does it take to be a Civil Engineer?  How do you know if you should pursue engineering as a career?   There isn’t a set type or hard list that can be used, but in general an Engineer is someone who wants to know how and why things work.  A good engineer is someone who can learn and then creatively apply that learning to different situations and applications.   Engineers by definition are problem solvers who create solutions to improve the world around us and to manage our natural resources.   Good interpersonal skills and an ability to communicate ideas are needed to succeed along with a love of learning.  As new technology, information and techniques are developed, the professionals in this field need to listen, learn and adapt to the continually changing needs of our society.   

Civil Engineering, as opposed to other types of Engineering, is concerned with designing, building
and maintaining public works.  Civil engineers work on construction, renovation, and rebuilding projects. Within the field of Civil Engineering there are various areas of focus including Environmental, Geotechnical, Structural, Hydraulic /Water Resources, and Transportation.  Civil Engineers often work with architects, technologists, and other industry professionals on a single project.  Depending on the project a Civil Engineer may have to split their time between working on design in the office and site visits to ensure the proper construction of their designs.  Some Civil Engineers may also be involved in reviewing government regulations, city ordinances and highway designs.

LAND SURVEYING AS A CAREER
Land Surveying is a profession which relies on legal analysis and science to determine the size, distance and position of the three-dimensional world around us.  Land Surveyors use the Law, Geometry, Trigonometry, Physics and Engineering Principles to produce official Plats, Mapping and Property Boundary Surveys. Land Surveyors also establish points of reference on the ground that are then used for things like geographic Information Systems (GIS), construction, land transactions and planning.  Attorneys, Civil Engineers, Property Owners and Governmental Agencies depend on Land Surveyors to provide them with accurate information about the land in order to divide property, transact property, plan improvements, maintain drainage and manage the existing natural resources.

MATH EVERY DAY
Anyone thinking of a career as an Engineer (any kind) or as a Land Surveyor should be proficient at math.  Both Civil Engineering and Land Surveying use their math skills on a daily basis.  While there are great advances in technology, programs and models to assist in their work, a good foundation and understanding of math is still essential.

TECHNOLOGY
As our society continues to improve technology, the information that a Land Surveyor or Civil Engineer has to work with is increasingly more precise.  GPS, Satellites, and Computer Software all aid the Land Surveyor in making accurate surveys, mapping topography and showing the shape, size and position of landmarks.  AutoCAD is a frequently used Computer Drafting program that allows the Civil Engineer to put their vision on paper.  Despite these advancements in technology, proper education and training is paramount to providing the public with an accurate and dependable final product.

FULL STEAM AHEAD
As the youth of today take interest in Science, Technology, Artistic Creativity and Math they will learn the skills needed to find solutions for tomorrow’s world, but they are not the only ones.  As business professionals, our Civil Engineers and Land Surveyors are required by law and a code of ethics participate in continuing education and development to maintain their edge on the ever advancing world of Technology.  

WHAT IS SWPPP?

STORM WATER POLLUTION PREVENTION PLAN [SWPPP]

             The Storm Water Pollution Prevention Plan is considered to be the most important 
              requirement of the General Permit. Each facility covered by this permit is required to 
             develop a plan, tailored to the specific conditions and with the primary goal of controlling 
             pollutants that may be discharged into storm water runoff.  (Illinois EPA.Gov)

As our country has developed, it has become increasingly clear that measures need to be taken to maintain our water resources and protect waterways from pollution.  Over the course of time laws have been created to prevent dumping of industrial waste, use of chemicals that can wash into the waterways and even testing of materials to be used in landfills.  All of this is aimed at the same goal: protecting the water.   This is part of the reason that SWPPP came into existence and is now an important part of the National Pollutant Discharge Elimination System (NPDES) permitting program. Any Construction Site that disturbs one or more acres is required to have coverage under the NPDES general permit for storm water discharges from construction activities.

MAKING A PLAN
Contractors typically have at least a vague notion of what a Storm Water Pollution Prevention Plan [SWPPP] entails even if they are uncertain as to exactly how or where it is to be implemented.  

              A SWPPP is more than just a sediment and erosion control plan.  It describes all the 
              construction site operator’s activities to prevent stormwater contamination, control 
              sedimentation and erosion, and comply with the requirements of the Clean Water Act. 
              (EPA SWPPP GUIDE pg. 1)

A good SWPPP will incorporate best Engineering Practices (BMPs) using knowledge of the hydrologic and natural features of the land.   In plain English that means a Civil Engineer will use the knowledge they have of the way the water travels to determine where there may be concern for damage to the environment or potential pollution to occur.   Since most developments will require a Civil Engineer in the planning stages, it is frequently the Engineer who will take care of the required Notice of Intent (NOI) to the IEPA and who can then provide the contractor with a SWPPP.  

PUTTING THE SWPPP INTO ACTION
When developing a site, the contractor then needs to make sure their staff are trained and understand the requirements and implementation of the SWPPP.   Some of these measures include:

     • How and where to install silt fence, 
     • Perform dewatering, 
     • Stabilizing Construction Entrance/Exit to minimize erosion
     • Designated Washout Areas for Concrete
     • Maintain Logs and Regular Inspections

Overall putting a good SWPPP into place is a necessary part of construction and development.   With the right measures contractors and developers can ensure that their project has minimal damage to the local environment by reducing polluted runoff, minimizing erosion and controlling sedimentation.
Need help preparing a Storm Water Pollution Prevention Plan on your next project?  Just Call (630-554-6655) or Email and we can help!

BMP: What is it & Why Do I Care?

Let’s start with what is a BMP?  In Civil Engineering and Construction, it typically refers to Best Management Practices.   The ‘Management’ part can vary, depending on who is using the term BMP’s.  A contractor may refer to Managing a Construction Project, but for Civil Engineering the term is almost always used in reference to stormwater and/or surface water runoff.  In general, Best Management Practices (BMPs) is a term used to describe thecontrol of water pollution; the best way to manage your land and youractivities to reduce or prevent pollution of surface and groundwater near you1.   There are a number of ways that pollution can be introduced to a body of water.  Once pollutants are present, it is more difficult and expensive to restore it to its former glory.  The use of BMPs that prevent damage to receiving waters is the target.

WHERE DOES THE RAINWATER GO?

Think back to the days of grade school and learning about the water cycle.  The very fundamental cycle of water and how it travels is the key to managing this resource in the best possible way.  Since water is a universal solvent, it easily picks up pollutants such as debris, metals, pesticides, sediment, bacteria, and more as it travels.  If left unchecked, the water can then carry these pollutants into lakes, rivers and streams.  For new developments part of their BMP will be a Stormwater Pollution Prevention Plan or “SWPPP”.  This Plan is developed and maintained throughout the construction phase of a project to ensure that the newly disturbed ground has a minimal impact on the natural water flow until the project is completed.   Another part of the BMPs for a new development will be the Civil Engineer’s Drawings showing how the earth around a building needs to be shaped, what elevations should be used and what the slope of the ground should be.   Along with the potential water quality issues, urban development can displace water and create an increase in flooding and add to the amount of water that is causing erosion or sedimentation.  These changes can also cause a change in vegetation and decrease of native wild life.  This is where Effective Management or ‘Best Management Practices’ (BMPs) become important.  Stormwater BMPs are techniques, measures or structural controls used to manage the flow and improve the quality of stormwater runoff and will be incorporated into the Civil Engineers Plans.

 

CONTROLLING THE FLOW

Typical BMP techniques used to control the flow of water and improve water quality include such measures as detention ponds, grass swales, natural plantings, and natural filters.  The techniques used for each development will differ depending on variables such as water table, typical rainfall, wetlands, overland flood routes, surrounding developments, and available drainage. 

By: Rashida Pflipsen / Rebecca Luginbill

¹ US EPA website:  http://www.epa.gov/nrmrl/wswrd/wq/stormwater/bmp.html