Sediment Dewatering Bags: All to Know
Maybe you’ve seen those giant dark bags of what looks like big inflated balloons at construction sites those are dewatering bags.
Sediment dewatering bags are made of a porous fabric that allows water to pass through while trapping sediment and other solid particles.
They are placed in problem areas where sediment has been known to accumulate, such as around construction sites, drainage ditches, and stormwater runoff areas.
In this blog post, we’ll take a look at sediment dewatering bags and all the things you need to know about them.
What is a Sediment Dewatering Bag?
A sediment dewatering bag is a type of water filtration bag that is designed to remove sediment from water. Sediment dewatering bags are often used in applications where it is necessary to remove sediment from water before it is discharged into a natural body of water, such as a lake or river.
Sediment dewatering bags are made of a durable, porous geotextile fabric that allows water to pass through while trapping sediment and other pollutants.
The bags are placed in an area where sediment-laden water is pumped, such as at the base of a construction site.
As the water and sediment flow into the bag, the sediment and pollutants are trapped inside. The clean water then flows out of the bag and is redirected away from the affected area.
Sediment dewatering bags are becoming an increasingly popular way to manage water with debris and sediment. They are easy to use and can be placed in a variety of locations, making them a popular choice for sediment removal.
There are many benefits of using sediment dewatering bags, including that they are a cost-effective way to manage sediment.
Additionally, they are a safe and environmentally-friendly option, and they can be used in a variety of different settings.
Why is Sediment Dewatering Necessary?
You might not think about sediment dewatering very often, but it’s a vital process that helps keep our environment clean.
Sediment dewatering is the process of removing water from sediment so that it can be reused or disposed of properly.
There are a few different reasons why this process is necessary:
- To improve water quality – Sediment can contain pollutants and other harmful substances. By removing the sediment, it helps to improve the quality of the water in receiving water bodies.
- To reuse sediment – Sediment removal from water makes it possible to reuse the sediment for other purposes. For example, it can be used as filler for construction projects.
- To reduce disposal costs – Dewatering removes water from the solids so that the solid particles can be transported without the weight and volume of the water. This way, waste disposal costs are reduced.
- To recycle water – Sediment dewatering removes water from sewage sludge so that it can be reused. This process is crucial because it helps reduce the volume of sewage sludge, a solid waste produced when water is treated.
- To minimize erosion concerns- Sediment dewatering is often used to minimize erosion concerns associated with sediment runoff. Removing sediment from running water makes the runoff less dense and less likely to cause erosion when it comes into contact with loose soil.
- To prevent damage to surrounding property- When rainwater or melted snow seeps into the ground, it can carry with it a variety of particles, including sediment. This sediment can then clog drains, damage septic systems, and even cause flooding. Dewatering sediment helps to remove these particles from the water before they have a chance to cause any damage.
How to Use Sediment Dewatering Bags?
Here are the steps to follow to use sediment dewatering bags:
- Connect the bags ‘neck’ or fill the spout (narrow section of the bag with an opening) to the hose (2-6-inch hose).
- Use the bag’s straps to tie the bag to the hose and ensure a secure fit.
- Alternatively, you can use a hose connected with clamps to screw your hose to the dewatering bag.
- Start pumping water through the hose.
- The sediment bag will trap all the solids and oils in the water.
- Once all the water is filtered, remove the bag from the hose and drag it to the disposal area.
- Empty the contents and dispose (for one-time use bags) or use the bag for another round of sediment dewatering if it’s reusable. It’s possible to cut open the bag and dispose of the contents if you only use it once.
- Disposal of the sediment should be as per the site engineer’s directions and the local regulations.
How do Sediment Dewatering Bags Work?
Sediment dewatering filter bags are typically made from a high-quality geotextile fabric. The fabric is woven in a way that allows water to flow through the fabric while trapping sediment and other pollutants.
These bags work by using internal water pressure. The water pressure forces the sediment to the bottom of the bag, where it’s collected. The water seeps out of the fabric’s tiny holes, making the bag.
For reusable sediment dewatering bags, locking rods are needed. The rods are used to secure the bag during the dewatering process, preventing the bag from opening and allowing the contents to spill out.
Bag locking rods are made of steel for strength and durability. They are typically placed at the top and bottom of the bag and are tightened to hold the bag closed during the dewatering process.
After the dewatering process is done, the locking rods are removed to dislodge the sediment and then re-attached for another round of dewatering.
Tips when using Sediment Dewatering Bags
- Monitor the contents of the bag as the water filters. Too much sediment may cause the bag to rapture, especially if it’s not a very good material.
- When there is an unreasonable flow of water from the sediment bag, it’s an indication that the bag is full. Stop the pumping, remove the full bag and connect another to continue filtering.
- If you’re using more than one bag, space them out so the water can drain properly. Otherwise, you risk the bags pooling water and becoming unusable.
- Place the dirt dewatering on a flat and porous surface if you want to maximize the water flow rate and the filtration of the sediments.
- It’s important not to add too much water at once when you begin adding water, as this could cause the sediment to loosen and filter back into the water.
- Always go for a large sediment dewatering bag, as the large surface area will make filtration even more effective.
- If you’re looking to transport the sediment for disposal in another area, place the bags and the truck and pump the water up there. This way, you won’t have to go through the hassle of loading the heavy bags on the transportation truck.
- If it’s time to remove a sediment dewatering bag from your hose, allow the water to drain out of the bag before you remove it. Otherwise, you could end up with a big mess (and a lot of wet sediment)!
Applications of Sediment Dewatering Bags
Dewater a ditch on a construction site
Dewatering ditches is a common construction site activity to prevent water accumulation and ensure safety.
For this purpose, construction workers often use sediment dewatering bags, which they connect with a hose to pump out the sediment-laden water. The bags work by absorbing sediments and oils and slowly release ‘clean’ water.
This allows construction ditches to be drained without having to excavate the sediment out. For most construction sites, turbidity status requirement also requires sediment removal.
Clean up a swampy area
If you have a swampy area on your property that you want to clean up, you can use sediment dewatering bags to do it.
These bags are designed to filter out sediment and other pollutants from water, so they’re perfect for use in wetlands and other natural areas.
Sediment and other debris are trapped in the bags, and the water is removed. This leaves the area clean and free of debris.
Remedy wastewater leaks
Sediment dewatering effectively reduces the amount of sediment that enters the environment during wastewater leaks.
There are two main ways to use sediment dewatering bags during wastewater leaks.
One common method is to place the bags in the area where the leak is happening. The bags will then collect the sediment as it leaks out. Once the bags are full, they can be removed, and the sediment can be disposed of properly.
Another way to use sediment dewatering bags is to create a barrier around the area where the leak is happening.
The bags can be placed in a line around the perimeter of the area. This can help to prevent sediment from leaking out and causing environmental damage.
Filter water from dredging locations
Dredging is the process of removing sediment from the bottom of a body of water.
This sediment can build up over time and cause the water to become shallow and murky. Dredging helps keep the water clean and clear.
Sediment dewatering bags are placed in the water near the dredging site. As the dredging process occurs, the sediment-filled water is pumped into the bags.
The water then drains out of the bags, leaving the sediment behind. The residue is then disposed of properly.
This process is beneficial because it helps to clean the water and keep sediment out of the environment. It also helps to improve the appearance of the water body and make waterways more navigable.
Pump power plant sludge
Power plant sludge is a type of waste produced by power plants. It’s typically a mixture of water, clay, and other contaminants.
Sediment dewatering bags are used to remove the water from the sludge, leaving behind the solids.
There are many benefits to using sediment dewatering bags to pump power plant sludge. For one, it’s a cost-effective solution. Additionally, it is a safe and environmentally friendly method of handling power plant sludge.
Factors to Consider when Buying Sediment Dewatering Bags
Size
The size of the bag will determine its capacity or the amount of sediment it can hold.
Common sizes for sediment dewatering bags are (3ft by 4ft, 6ft by 6ft, 7ft by 8ft, 5ft by 15ft, 12ft by12ft, 12ft by 15ft, 10ft by 15ft, and 15ft by 15ft). The most common size option for typical dewatering projects is 6ft by 6ft.
For large projects, though, you need a larger bag such as the 15ft by 15ft. A 15ft by 15 ft. bag can pass around 500 gallons of water per minute and hold about 259 cubic feet of sediment.
Efficacy
Efficacy is the ability of the bag to actually filter out sediment. Some bags are more effective than others, so it is essential to find a bag that will be effective at sediment control.
There are a few different ways to measure efficacy.
One is the sediment removal rate, which is the amount of sediment the bag can remove from water over a period of time.
The other is the sediment retention capacity, which is the amount of sediment the bag can hold before it needs to be emptied.
The sediment removal rate and sediment retention capacity are both crucial factors to consider when choosing a sediment dewatering bag. Be sure to compare different bags considering these factors before making your final decision.
Cost
Sediment dewatering bags are typically priced per bag, but the good thing is that they’re inexpensive.
For $70-$100, you can get a decently-sized and good-quality sediment dewatering bag. However, it’s important to compare prices before making a purchase.
Make material
Regarding the material type, you need to choose a dewatering bag made of a strong material that can hold up sediment without rupture.
You’ll also want to choose a durable material that can withstand the elements.
Are Sediment Dewatering Bags Reusable?
There are many different options available when it comes to dewatering bags.
Some are designed for single-use, while others can be reused multiple times. A reusable dewatering bag might be a better solution if you’re working on a large project or are on a tight budget.
Reusable dewatering bags are made of a durable geotextile material that can withstand multiple uses.
They are also often more expensive than their disposable counterparts. And because they can be reused, they are a more environmentally-friendly option.
What determines sediment dewatering bag flow and removal rate?
When you’re working with sediment dewatering bags, there are a few things that will determine the flow and removal rate.
The type of sediment, the amount of water, and the size of the bag all play a role in how fast the water will be removed.
What is the difference between dewatering bags and dewatering tubes?
Dewatering bags are small, usually, round, bags made of durable fabric that can be filled with water to filter out sediment and debris.
Dewatering tubes are much larger (up to 50 feet long) and are used for projects requiring a large volume of water to be filtered.
Wrapping Up
Sediment dewatering bags are a type of filter bag that is used to remove sediment from water.
The bags are filled with sediment-laden water and then placed on a porous surface. The internal pressure squeezes the water out of the sediment, leaving the sediment behind in the bag.
Sediment dewatering bags are easy to use and can be placed in a variety of locations.
This article provided an overview of sediment dewatering bags, including how they work and how to purchase one.
Hopefully, you now know what to use to trap sediment when pumping water out of your construction site or agricultural field.
