Rhodes, Author at 3R Incorporated

24/7: (864) 848-1312

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Maritime Dredging: How Often is it Needed?


The short answer is that Maritime Dredging is needed as often as it is required. We’re going to drill down a bit into exactly what that means, and how to figure that out, but every dredging project is different. There are different inflows, different dredging requirements, and different budget considerations that will determine the dredging frequency that is required for your project. This is what makes hiring a dredging consultant so important.


Maritime Dredging How Often - Crane Dredge


Considering your options? Check out our post on the Top 5 Dredging Consultants.


The reason it’s so hard to determine the exact dredging frequency, or dredging cycle, is that every climate, body of water, and water use is very different. Take the Chesapeake Bay region, for example, you’ll see official dredging cycle estimates ranging from 2 years, to 200 years depending on the type of use, and the required level of dredging.


That report also points out a range of dredging and the frequency required for each project. The Broad Creek navigation channel has an estimate of 5 years for high bound dredging, and 20 years for low bound dredging – with the “most probable” dredging cycle falling somewhere in the middle at 10 years.


The reason for the range of years really has to do with costs. The high bound dredging cycle is expected to carry an annual cost of 401 k, versus the low bound annual cost of just 34k. The most probably dredging cycle of 10 years carries an annual cost of around 108k. It’s a good balance between annual cost, and when dredging will be absolutely required.


In the Gulf region, dredging of shipping channels is required every couple of years. Without dredging, shipping traffic wouldn’t be able to safely pass through the region.


Determining Your Dredging Frequency

The number one factor in determining your dredging schedule is the reason that you’re dredging. If you’re dredging because you need an absolute minimum depth for ships, then your frequency will be fairly regular and determined by that cycle. If you’re dredging just to create a healthier and deeper body of water, to remove contaminants, or to restore fish habitat, your schedule may not be as rigid.


Marine Dredging How Often - Coral Reef


Determining your dredging frequency requires looking at several factors:

  • Depth Required – What depth do you need to maintain? This would be the absolute minimum depth that you will allow the body of water to reach. You’ll want to factor in a safety buffer if the depth is mission critical, like for navigation routes or ports and harbors.
  • Dredging Depth – How deep can you dredge? If you can only dredge a few feet versus a few dozen feet, this will determine how often you’ll need to dredge the same area. Obviously, 2 feet will fill up much quicker than 20 feet and will need to be dredged more often.
  • Inflow Considerations – How quickly do silt and debris fill in the body of water? Although dredging is often measured in cubic yards, we’ll simplify this a bit. If you have a 10-foot lake that you’re dredging to 25 feet, (assuming 10 feet is the minimum depth) you can allow 15 feet of silt and debris before dredging is required again. If you lose 1 foot of depth per year, that gives you a 15-year cycle. However, if you lose 5 feet per year, you’re now on a 3-year cycle.


Overdredging to Reduce Frequency

One method that is employed by the military is to overdredge certain areas to reduce the dredging frequency.


A dredging practice widely used by the Corps’ Coastal District offices in maintaining navigation projects is that of overdredging, often referred to as advance maintenance dredging. The Corps currently uses overdredging to maintain 300 estuarine and coastal navigation projects. Overdredging, or advance maintenance, can either be in the form of overdepth or overwidth dredging.


Dredging can be disruptive, so the ability to lengthen the frequency of dredging can be very beneficial to regions that require dredging every couple of years. By simply digging deeper and wider than what is normally required, it will take longer for the area to fill in to the minimum required depths.


There is a larger cost associated with overdredging, but this is usually offset by the reduced frequency.


It also may not be possible to overdredge in your area. It really depends on the regulations that you’re working with. Sometimes only minimal dredging is allowed to take place, which will also increase the frequency of your dredging project.


Reputable Dredging Companies

It’s important to hire a company that will be able to guide you through the process and offer a frequency that fits your budget – and gets the job done. There’s nothing worse than having to dredge a body of water only to find out it needs to be done again much quicker than anticipated because the company didn’t estimate properly


Find an experienced company that offers premier dredging services that will be able to lean on past projects to help you properly estimate dredging frequency.


Give us a call at (864) 848-1312 or email us at admin@3rinc.com.

Top 5 Dredging Companies

Dredging is not an easy task. It can take months of planning and years of hard work to get the job done right. During this process, there is plenty that can go wrong if you hire the wrong company. This includes spreading around contaminated soil while dredging – otherwise known as resuspension – which can increase the problems you’re facing. That’s why it’s important to do your homework and hire a company you know can get the job done.


When looking for a marine dredging company, it’s important to look at their history, the type of dredging they offer, and the success stories they have in their portfolio. Although it’s impossible to eliminate every possible issue that may come up in the process, hiring an experienced firm will help minimize the surprises.


If you’re considering dredging, here are the top five companies to take a look at for your project.


Number 1: 3R Inc. – Industrial and Environmental Contractors

3R Inc. tops our list for one main reason: they’ve done it all. With two decades of environmental remediation under their belts, they can handle pretty much any dredging project you throw at them with the latest techniques and equipment.


When hiring a company, dredging may be your number one priority, but hiring a company that offers so many different services will give you the reassurance that the job will be done right no matter what pops up.


3R Industrial & Environmental Contractors Logo


Beyond just dredging, 3R Inc offers Disaster and Emergency Responses, Emergency Waste Disposal of Hazardous and Non-Hazardous Materials, Pit and Pipe Cleaning, Grease Traps and Oil/Water Separators, Waste Transportation and Coordination, Remediation, Tank Cleaning and Removal, Sewer Cleaning – and a whole lot more.


As one of the companies on the scene for 9/11, they really have experienced the worst possible cleanup conditions. They’ll be able to handle your dredging project with ease. Don’t take our word for it, check out their premier dredging services for yourself.


Number 2: Norfolk Dredging

If you want history, this company has it. With over 100 years of dredging under its belt, Norfolk Dredging makes the list at number 2. A company with such rich history scores very well, but the reason it’s not the number one company is just that: its history. The current equipment that is deployed is decades old. Although some newer equipment is available, you’ll want to make sure your dredging project is being handled with the right equipment.


Although they have many successful projects listed, there is a reason many companies have popped up over the last half century (including those on this list), and that’s because technology and environmental requirements are constantly changing.


Of course, a company doesn’t stick around this long without doing something right, and Norfolk Dredging does plenty well. Just make sure you do your research to ensure they’ll work for your project.


Number 3: Coastal Dredging Company

Coastal Dredging Company is another dredger that focuses “primarily on wetlands restoration and mitigation, oilfield channels, habitat enhancement, levee construction, pile driving and installation of water control structures.” If you’re in the market for those services, this company may be the one for you.


The website is a little thin, but it does give you a look at the technology they use, and some of the projects they’ve completed. Although they’ve been around for 20 years, they only list past projects that go back about 8 years. This is likely due to the scope of smaller projects they were performing previously.


The company is small in size but does have a good reputation among clients, so it makes our list at number 3.


Number 4: Gulf Dredging

Gulf Dredging is another company with a long history of completing dredging projects. Although they don’t offer as many specialties as 3R Inc., they are great at dredging if that is your main concern.


Their portfolio consists of a number of government and civilian projects, and they do spend a considerable amount of their resources in offshore projects. The only reason they don’t top the list is that they specialize in reclamation and offshore construction, which won’t fit the needs of everyone. It’s a more narrow focus that other’s on the list, and although they’re not as nimble as 3R Inc. in their offerings, they are a more than capable dredging company.


Number 5: Great Lakes Dredge & Dock Company

Another company with100-year history rounds out our list. Although GLDD primarily focuses on the Great Lakes, they’ve been the primary company responsible for making sure those waters are navigable to the cargo ships that use it.


The Great Lakes feature a number of unique challenges, including freezing during the winter, that puts GLDD onto this list. This company has a track record that is not only impressive, but they offer a variety of equipment to tackle all scenarios.


No matter what your dredging project calls for, do your research and choose the company that will work for you. Choosing the right company will go a long way to ensuring a successful project!

Hiring Dredging Consultant - Mechanical Dredge

Hiring a Dredging Consultant: 5 Things to Know

If you’re considering marine dredging, there are a significant number of options to choose from. There are also a number of obstacles and difficulties that pop up in any project. The first place to start is with a marine dredging consultant. There are many benefits to dredging, and your consultant will walk you through the whole process, make sure you don’t forget about any details, and help your project to succeed with the fewest surprises.


So what do you look for when hiring a marine dredging consultant? If you don’t know much about dredging, how would you know if the consultant or company you’re looking at is any good? Here are 5 things to look for that will help you make the right choice.


Dredging Experience Matters

A lot of problems can pop-up with dredging. That’s not to scare you, it’s just a reality. You can kick up unwanted contaminants, your dredging equipment may not be able to handle the whole job, and you need to protect wildlife habitats during the process.


Experienced professionals will give you the best shot at avoiding any surprises. Whatever scenario you’re looking at for your marine dredging project, chances are they’ve seen it before. The more you can prepare, the less likely something will go wrong.


Check out their Portfolio

Any reputable company or consultant will have a portfolio of work they can show you. What you’ll want to look for is a range of projects and their outcomes. If the firm only has a few projects that are very narrow in scope, you’ll want to make sure this is exactly the type of scope you’re looking for. If it’s not, they may not have the experience needed to handle your dredging project.


Hiring Dredging Consultant - Pond Exposed to Heavy Sediment Build Up


All dredging is not created equal. A firm that only has small ponds on in their portfolio may be ill-equipped to handle a stream or port project. Looking for a variety of projects and outcomes is the best way to ensure they have the experience needed to overcome any obstacles.


Talk to References

The marine dredging consultant should be able to provide a few clients you can talk to about the project. These clients will be able to give you a real good look at the entire process. A few questions you may want to consider asking:


  • Did the project come in on budget? It’s ok if the project was over budget as surprises do happen. What you want to look for is whether projects consistently come in over budget, and by how much. If references are constantly saying they paid triple the expected costs, that’s a red flag.
  • Was the project completed on schedule? Again, there are many variables here that can cause a project to extend past a scheduled end date. What you’re looking for is how often this happens, and by how much the projects were extended.
  • What was it like to work with the consultant? Get the general sense of what it’s like to work with the people you’re hiring. Are they great communicators? Was there any part of the process the client didn’t like? Large projects are not something you want to work on with a company that has a reputation for being difficult to work with.


If the company or individual is reluctant to offer references, you’ll need to ask why that is. Great companies with great reputations wouldn’t have a problem providing this information. In fact, they’ll often have examples ready to go.


Equipment Matters

Not all dredging is created equally. Different equipment is needed for different types of dredging. We’ve touched a bit on this in the past by pointing out the differences between mechanical and hydraulic dredging.


Find out the various options that are available for your dredging project. One size doesn’t fit all. Some methods of dredging are better than others. There’s a big difference between a backhoe on a barge and a high-tech hydraulic vacuum.


Understanding Pricing

Lastly, understand the pricing. What’s included, what’s not. What cost overruns you should prepare for. What are the best case scenario and worst case scenario costs to your project. The more information you get here, the better prepared you’ll be to handle any surprises.


Our process involves a comprehensive dredging quote that will give you all the information you’ll need to make an informed decision. There’s no obligation, and we’re likely to help steer you in the right direction, even if you choose another firm for the final project. We’re confident you’ll be very happy with what we can offer.


When hiring a marine dredging consultant, make sure you feel comfortable with all the above points. Ask questions, be involved, and you’ll ultimately be able to make the right choice. If you have any questions about the dredging process, don’t hesitate to contact us and we’ll do our best to help you out.


Give us a call at (864) 848-1312 or email us at admin@3rinc.com.



Marine Dredging How Often - Coral Reef

How Marine Dredging Affects Wildlife: A Comprehensive Study

There’s no way around it: marine dredging affects wildlife. What you may not be aware of is that it often affects the wildlife population positively over the long term. Although dredging may negative effects during the actual act of dredging, these can be minimized and are often very short term while the work is being performed. The key is to hire a professional marine dredging consultant to ensure you’re minimizing the impact.


So what exactly happens during and after marine dredging? How will wildlife react? What can be done to minimize the impact? We’ll take a look at all these questions to get a better understanding of what dredging does, and does not do, to affect wildlife.


How Marine Dredging Helps Protect Wildlife

The reason for the dredging is just as important as the dredging itself. If you’re dredging to remove contaminated soil, or if you’re doing it to restore depth to a lake that is disappearing due to erosion, the benefits to wildlife are fairly obvious: you’re repairing or maintaining an environment that they require to survive and stay healthy.


Marine Dredging Affects Wildlife - Saltwater Fish


What may surprise you is that in most cases dredging doesn’t even affect fish levels. Although it can be disruptive during the actual act of dredging, the issue has been well studied. California has studied the issues extensively and have noted these studies in dredging laws:


“…the Department finds that suction dredging subject to and consistent with the requirements of Sections 228 and 228.5 will not be deleterious to fish.”


Dredging doesn’t start and stop with the act of removing material. Consideration must also be given to all aspects of dredging – including what happens to the dredged material. Simply moving the problem around won’t solve anything.


Although dumping dredged material in the landfill won’t hurt anything, it could be more more effectively used to promote wildlife elsewhere. The US Army Corps of Engineers have actually studied the issue and found that there are many uses for dredged material that can benefit the environment and wildlife beyond the dredging site itself.


Minimizing the Impact of Dredging

It’s important to take every step possible to ensure the type of dredging you’re looking to employ. We’ve already talked at great lengths about the differences between mechanical and hydraulic dredging, but there are positives and negatives depending on what you’re looking to accomplish.


When done properly, dredging can have almost no impact on wildlife. This is why it can often be accomplished in very sensitive environments. It might seem obvious that no dredging would ever be allowed in a national wildlife refuge, but it may surprise you to know that’s not the case. Dredging is one activity that has constantly been permitted by governments in these sensitive areas when done correctly.


“Negligible displacement could potentially occur during dredging, but no significant migratory waterfowl patterns would be impacted as a result of dredging.”


This is why: it’s important to hire firms that provide quality dredging services. Firms with a track record of environmental protection will have a much better chance at getting approval to perform the work. Having the right experience and tools can make all the difference in your dredging project.


Potential Negatives to Dredging

One major way in which dredging can negatively impact wildlife is when it’s done incorrectly. One study showed that even with the best intentions, dredging can have negative consequences:


“Technical constraints, like underwater obstacles, can prevent dredging equipment from accessing sediments and dredging can uncover and re-suspend buried contaminants, exposing wildlife and people to toxicants.”


It’s important to note that even with the best preparation and most experienced contractors, there are always unknowns. Of course the more experience you hire, the more likely you are to eliminate surprises, but this can never be entirely mitigated.


In other cases, dredging is necessary, but it is altering the wildlife landscape. In one case outside of New York City, the Hudson is being dredged to clean contaminants from the riverbed. Although most people would say this is very important work, it’s not entirely without consequences:


“Dredging and capping/backfilling activities in the Upper Hudson River are destroying mussel beds and mussel habitat, which are not being replaced as part of the remedy for the Hudson River PCBs Superfund Site.”


The best way to mitigate the potential impacts is not to stop dredging, as removing contaminants is clearly the priority, but to find a way to restore the environments as required. This is where the short-term impact of dredging can be a real problem, but the long term benefits far outweighs these short term concerns.


Working with Experienced Professionals

We can’t stress this enough. Experience can do wonders to protect wildlife during the dredging process. If you destroy an ecological area, it can take decades or centuries to recover. It’s important that you do your research first, to ensure you’re making the best decisions possible to minimize the impact of dredging.


Marine Dredging Affects Wildlife - Crane Dredge


If you have any questions about dredging or what’s involved, contact our team to find out the options available to you. We take the environment very seriously, and have been involved in many environmental cleanup disasters, so we know how fragile wildlife habitats are. Safety and wildlife protection are our top priorities. For a free consultation, fill out our brief dredging quote form today!


If you’re interested in having a conversation, pick up the phone and call us at (864) 848-1312 or email us at admin@3rinc.com.

Dredge Lake Guide - Pond Exposed to Heavy Sediment Build Up

How to Dredge Your Lake Effectively: An Owner’s Guide

Dredging a lake is a massive undertaking, so you’ll want to make sure you get it done right the first time. It’s important you take a look at all the different options, costs, and results you’re looking to achieve by dredging. The last thing you need are cost overruns, environmental damage and huge cleanup costs from a botched job.


We’ve taken a look at dredging before, but the basic benefits of dredging are highly recommended by the NOAA:


“Dredging is the removal of sediments and debris from the bottom of lakes, rivers, harbors, and other water bodies. It is a routine necessity in waterways around the world because sedimentation—the natural process of sand and silt washing downstream—gradually fills channels and harbors.”


If you know you need dredging for your lake, here’s a quick guide to help you get started.


Preparation, Preparation, Preparation!

As previously mentioned, you’re going to want to spend a good amount of time planning the operation. It’s best to work with a reputable company during the planning and preparation stage. They’ll be able to walk you through the whole process and everything required with the dredging – and hopefully, leave you with no surprises. We’ll touch on choosing a reputable company later.


A great example of planning comes from Illinois. Their fact sheet gives you a two-page overview of the program they’ve implemented, and how they’re tackling it in stages. You’ll note that their fact sheet includes a background, the current problems the lake faces, and their chosen method to solve those problems.


Determine what kind of Problem you’re Solving by Dredging

Determining the type of dredging you require will go a long way to helping you choose the right teams and methods to tackle that dredging. Here are a few different reasons you may need to dredge:


Preventative Dredging – This is one of the most common forms of dredging for shipping channels and ports. They need to dredge before any problems occur. By ensuring water depth is available to large ships, and removing any foreign materials on a regular basis, they don’t wait until they notice a problem to dredge. If you’re looking to be proactive with your dredging, this is where you start.


Restoration Dredging – This type of dredging occurs after some damage has already been done. A great example is a lake over in the United Kingdom that had never been dredged in its entire 150+ year history.


“High levels of silt are impeding plant development and also mean that particular plants such as water lilies and reeds are dominating the lake. Silt is also building up on root mass in and around the lake and affecting the shrubs and trees both in the lake and on its edges. Without intervention, the lake would eventually silt over entirely and become a swamp.”


This type of dredging will likely be needed if you’ve noticed your lake isn’t quite a lake anymore. You likely need to start here if shorelines are facing constant erosion and invasive plants are taking over.


Mechanical vs Hyrdaulic - Dredging in Areas of Industry Such as Harbor



Contamination Dredging – This is the worst type of problem to have. It likely means some damage is already being done. This is common in ports and lakes where a spill has occurred, or as metals build up on the lake floor from boat traffic.


It also means you’ll need to choose the right type of dredging equipment in order to ensure the contaminants aren’t being spread around. This is where resuspension is an important topic. The US Corp of Engineers has done a lot of work on resuspension and why it’s important if you’d like to read more.


Depth Dredging – Need a deeper lake for boating, or to better support fish stock? Dredging for depth is another fairly common reason you’d need to undertake this task.


Choose a Dredging Technology that works for You

We’ve already covered the major differences between hydraulic and mechanical dredging, but here’s a quick recap:


Mechanical – Often uses a large crane or backhoe to remove material with a bucket digging down. Lake may or may not need to be drained to employ this method. Great for removing large objects.


Hydraulic – More like a vacuum that sucks up silt and debris. It’s often friendlier on the environment. It won’t remove larger objects though.


Dredge Lake Guide - Mechanical Dredge


There many pros and cons to each type of dredging and some methods work better than others.


Look for Reputable Dredging Companies

Lastly, you’ll want to work with reputable companies when dredging a body of water. Most companies will have a track record you can view. If they don’t have any information on previous clients, that’s a bad sign.


You’ll want to review the work and techniques they’ve used in the past, along with any cost overruns or work disruptions. It will give you a good idea of how they handle any unforeseen issues. The cheapest bidder isn’t always the best option – and can cost more in the long run. Reputation means something in this industry.


Dredging is a complex process that involves a lot of planning. If you have questions about your project, let us know and we’ll do our best to answer them!


Email us at admin@3rinc.com or call us at (864) 848-1312.

Mechanical vs Hyrdaulic - Which is right for you

Mechanical vs Hydraulic Dredging: Which Method is Right for You?

There’s more than one way to dredge a body of water, but each one has pros and cons. The type of dredging you require will really depend on the body of water you’re working in, and what your goals are.


In many cases, both types of dredging are effective, but depending on the cost restraints, equipment access, and how fragile the environment is, one method of dredging may be better than the other. The first thing is to fully understand the difference between mechanical dredging and hydraulic dredging. We’ll take a look and each type, and why each method may or may not work for you.


Although mechanical and hydraulic are the two main groups of dredges, each group can be broken down even further into specific dredging equipment and methods, we’re just going to explore the main groups in this article. The exact equipment that’s right for your job will depend on a lot of factors.


Sediment Resuspension

One Major issue that factors into all types of dredging is resuspension. To sum this up neatly, it’s basically when you start poking around the bottom of a body of water, you’re likely to kick up all kinds of material – some organic, some man-made, and some of which isn’t very good. Usually, contaminants are contained within a layer of silt, which gets kicked up with ship and dredging activity. Generally this problem is worse in harbors and areas where industry is present, however, this problem can appear anywhere.


Mechanical vs Hyrdaulic - Dredging in Areas of Industry Such as Harbor


Uncontrolled resuspension could remobilize weakly bound heavy metals into overlying water and pose a potential risk to aquatic ecosystem.


Whenever resuspension is an issue, you’ll need to put more thought into how disruptive the dredging technique is.


What is Mechanical Dredging?

Mechanical dredging is using heavy equipment to “dig” the bottom up and remove it. This equipment is usually brought in on a barge, or works while the body of water is drained. The equipment used can be very similar to that of residential construction equipment where a bucket is sent down to haul up dirt and remove it.


Mechanical vs Hydraulic - Mechanical Dredge


There are also many specialized pieces of equipment that are used to drill or dig up the dirt on a more continual basis. Think of a mining operation where minerals are constantly being cut from the wall and conveyed to a holding area. It’s a very similar process.


The type of mechanical dredging that is prefered really depends a lot on the size of the water, and the access you have to it.


One major issue with mechanical dredging is the inability for it to ensure all the sediment or contaminant.


Resuspension and contaminant release by mechanical dredges may result from dynamic impact of the bucket with the bottom sediment (for wire supported buckets), sloughing of material into the cut, washing of sediment from the bucket exterior as the bucket is raised through the water column, and leakage from the bucket (either from the top of an open bucket or from the lips of the bucket if closure is not complete due to debris). All these mechanisms result in a pattern of resuspension and contaminant release that may be exhibited both near bottom and in the full depth of the water column.


Basically, when you’re digging down with a bucket, you can’t ensure that you’re getting everything off the bottom that shouldn’t be there, or how much you’re kicking up by just digging around. While you’re brining the bucket up, you contaminant can fall out, off, or through the bucket. If your dredging goal is to remove something specific, this type of dredging may not work well.


What is Hydraulic Dredging?

Unlike mechanical dredging, hydraulic dredging doesn’t use a “scoop” to remove the silt. It works more like a vacuum cleaner to suck up and filter the bottom to remove contaminant and create depth. It’s a little more complicated than that, and there are a few different methods you can use, but that’s the basic way that it works.


Mechanical vs Hydraulic - Hydraulic Dredge


Studies have shown that when environmental sensitivity is a major concern, Hydraulic dredging seems to be the more effective method.


“Dredging methods can be assessed and ranked with regard to their environmental effectiveness (Van der Veen, 1993). Purely mechanical approaches such as grab cranes and digger buckets have the lowest ranking of the existing methods. The highest scores can be assigned to the combined mechanical/hydraulic techniques and these can be the most effective in dredging contaminated soils.”


The Government of Texas also found that hydraulic dredging was the preferred method as it produced among the lowest resuspension rates of common dredge types.


It’s not all roses though. Hydraulic dredging isn’t meant to dredge large or heavy bottom materials like rocks. Although smaller stones and objects aren’t a problem, it works best with fine silt and sediment. if you’re removing an old rocky bottom, mechanical would likely be the only solution.


Quite often a combination of dredging techniques can be used to achieve the greatest results in terms of outcome and efficiency. The only way to know for sure is to contact a professional to help you determine exactly what type of dredging is appropriate for you.


Contact us at (864) 848-1312 or admin@3rinc.com for any dredging questions or quotes.

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