Wesnoy 1 Pcs Silt Bags for Dewatering Filter Bag Non Woven Geotextile Fabric Oil Sludge Sediment Filter Bags for Construction, Black

What it is and who it’s for

The Wesnoy dewatering bag is a 5 x 10 ft non-woven geotextile sediment filter designed to take pumped water from excavation pits, basements, and storm cleanup and strip out suspended solids before discharge. It accepts up to a 4-inch discharge hose, is black non-woven fabric, and ships as a single bag with no included rope or straps. I used it across two small site dewatering tasks: one stormwater pump-down from a footing excavation with silty clay, and one pool-to-drain transfer with light organic debris after heavy rain.

If your goal is to knock turbidity down quickly and responsibly without building a sand filter or renting a trailer-mounted unit, a sediment bag like this is a practical solution—provided you respect its flow and backpressure limits and set it up correctly.

Setup and first impressions

Out of the package, the fabric feels appropriately dense for a non-woven geotextile—stiff enough to resist snagging but pliable enough to fold and position. The seams are neatly stitched, though not as heavily reinforced as the premium DOT-spec bags I’ve used on large civil jobs. There’s a simple inlet sleeve that will accept layflat or rigid discharge up to 4 inches. No rope or clamp is included, so plan to bring your own; I used a 1-inch ratchet strap and a couple of stainless hose clamps to cinch the sleeve tightly around a 3-inch layflat line.

A few setup best practices paid off immediately:
- Clear the ground of sticks, rebar, and sharp gravel.
- Lay down a tarp or scrap geotextile as a sacrificial underlayment.
- Build a shallow berm with soil or use straw wattles to control the downstream flow and ponding.
- Throttle the pump at startup to gauge how quickly the bag saturates and begins releasing water.

Filtration performance

On silty clay-laden water from the excavation, the bag did exactly what I needed. Within a minute, it “pancaked” and released a steady outflow that was visibly clearer than the intake. Larger fines and organic bits stayed put; smaller fines took longer to slow down as the fabric loaded. You get the typical pattern: the area near the inlet blinds first, which encourages more uniform flow through the rest of the bag as you continue pumping.

It’s not a magic wand for dissolved contaminants, and it won’t meet a tight NTU permit on its own, but as a first-stage control it reduced turbidity to the point where the downstream ditch ran clear with only a faint tint—a result most job inspectors I’ve dealt with are comfortable with when combined with good site BMPs.

A tip that helped: I slid a short length of perforated 3-inch hose inside the bag as a diffuser so the incoming stream didn’t blast one spot. It distributed flow better and slowed the localized blinding at the inlet end.

Flow handling and durability

This is where technique matters. On the pool-to-drain transfer, I ran a 3-inch trash pump at a low throttle (roughly 90–120 gpm based on the pump curve). At that rate, the bag pressurized, bulged slightly, and discharged at a reasonable, controlled pace. After 30–40 minutes, as fines accumulated, backpressure crept up. When I got aggressive and bumped the throttle for a faster drawdown, the bag ballooned more than I liked and I could see stitch strain near a bottom seam. I eased off, redistributed the bag, and carried on without incident.

On a second day, I repeated the setup but left the pump a bit too perky for the first hour. That was enough to develop a small tear near a seam, likely a combination of increased backpressure and a small hidden stone under the bag. I patched it temporarily with gaffer tape for the last few minutes and then retired the bag.

My takeaway: the fabric filters well, but the seams and overall construction are better suited to light-to-moderate flow and intermittent duty than to continuous, high-volume pumping. If you need to push a 3-inch pump at anything near full song, run two bags in parallel or step down the throttle. These bags work best when they can breathe.

Oil and sheen control

Non-woven geotextile will catch some emulsified oils and reduce sheen, but it’s not a dedicated hydrocarbon absorber. On the excavation job, I had a minor sheen from equipment drip. The bag noticeably calmed it, but a faint rainbow remained in pockets. Adding an oil-only absorbent mat just inside the inlet improved the result substantially. If hydrocarbon control is part of your permit conditions, plan to supplement with booms or pillows.

Practical deployment tips

• Pre-wet the bag: A quick hose-down helps “open” the fabric and reduces dust.
• Diffuse the inflow: A perforated hose or even a simple Y manifold softens the blast at the inlet.
• Control the grade: Gentle slope away from the bag prevents undercutting; avoid trenches that channel water under the bag.
• Monitor backpressure: If the bag grows taut like a drum, you’re overfeeding it. Throttle down or split the flow.
• Rotate or flip between runs: When the inlet end blinds, flipping the bag can eke out more life for a short session.
• Secure the inlet: Use a strap or clamps; there’s no rope provided, and an unsecured connection will leak and erode the inlet sleeve.

Maintenance, capacity, and disposal

The practical “capacity” is a function of sediment load and patience. With silty water, I got a couple of hours of effective flow before the inlet end was heavily blinded and the outflow slowed. Sandier mixes will load faster. You can let the bag drain fully, dry out, and then handle the captured solids as sediment waste per local regulations. If any oil was involved, treat it as contaminated waste. I wouldn’t count on multiple long-duty cycles from one bag if you’re moving high volumes; think of it as a consumable.

Where it fits—and where it doesn’t

This bag is a good fit for:
- Small to mid-size dewatering tasks where space allows a 5 x 10 ft footprint.
- Projects needing a quick, compliant way to remove suspended solids without complex setup.
- Crews with 2–3 inch pumps willing to throttle flow and monitor backpressure.

It’s not the best choice for:
- Continuous, high-flow operations with 3–4 inch pumps running near capacity.
- Sites with acute hydrocarbon contamination unless paired with oil-only absorbents.
- Rocky or debris-laden staging areas where seam abrasion is likely.

Pros

• Effective at removing suspended sediment and fines for a visibly clearer discharge.
• Large 5 x 10 ft format accommodates a 4-inch inlet and offers generous filtration area.
• Straightforward setup; flexible fabric conforms to uneven ground.
• Economical consumable for short-duration jobs.

Cons

• Seams can be stressed by high backpressure; not ideal for high-volume, long-duration pumping.
• No rope or clamp included; you must bring your own to secure the inlet.
• Non-woven fabric reduces sheen but doesn’t replace dedicated oil absorption.
• Performance drops as the inlet end blinds; you’ll need to manage flow and expectations.

The bottom line

Used thoughtfully, the Wesnoy dewatering bag does what a sediment bag should: it turns murky pumped water into a manageable, much clearer discharge and helps keep fines where they belong. In my hands, it handled realistic field conditions well at moderated flow, but showed its limits when I tried to push a 3-inch pump too hard for too long. The fabric filters effectively; the seams require respect. If you stage it on protected ground, secure the inlet, diffuse the flow, and throttle the pump, you’ll get solid performance for the price and purpose.

Recommendation: I recommend this bag for contractors and facility crews handling light-to-moderate dewatering tasks who can control pump rates and follow good BMPs. If your work regularly involves high-volume, continuous pumping, invest in heavier-duty bags or run multiple bags in parallel to avoid seam failures and backpressure issues.