Frequently Asked Questions

The time really depends on the amount of incoming sludge and capacity.  However, most lagoons require dredging every 5 to 10 years on average. Some lagoons that treat or capture organic matter can be aerated and treated to extend the timeframe.  Sludge depth can be monitored to provide data for timelines and planning of the next dredge. 

Many landscapers, contractors, operators, and property owners have only seen standard grading equipment moving dirt on a project or on the side of the road.  Many machine operators and contractors only have equipment designed for moving dirt and grading.  Dredging is different and there is a variety of specialized equipment specifically designed to get silt, sand, or muck out of a pond, lake, or lagoon.  Long reach excavators are one machine designed to reach 2 to 3 times further than regular excavators.  Hydraulic dredges are barges that float on water to enable them to vacuum up silt from the bottom of a lake.  They come in all sizes and may be the best solution for your project. 

Dredging is a method to clean the silt or sediment out of a pond on a golf course.  Restoring a golf course pond’s appearance and capacity to store irrigation water can be beneficial to both the manager and players.  Dredging can occur with limited impact on the course and even while play continues.  Golf course ponds can be dug out with an excavator or the silt can be pumped with a dredge and dewatered nearby or a long distance away. 

Many water treatment plants are designed to store raw water within a reservoir prior to treatment.  If your reservoir is losing capacity as a result of sedimentation, dredging may be the best solution.  Dredging can remove the sediment without lowering the water level, and use of NSF polymers ensure that drinking water supply continues safely.  Hydraulic dredging is a preferred method to dredge the sediment while the water remains in the reservoir. 

Cleaning out sediment ponds at a quarry can be tedious.  Draglines were used in the past but have mostly been replaced by excavators to dig out settling ponds.  Hydraulic dredges can also be useful to remove sediment from ponds in mine sites and quarries.  Tailings, silt, and sediment can be removed and used in reclamation activities or placed in areas outside of the main processing facility. 

A lagoon or pond at a wastewater treatment plant can be dredged to remove excess sludge.  First a dredge is placed in the water and connected to a pipeline.  An auger dredge is best for this application.  The dredge is propelled with a cable that is anchored along the shoreline.  The dredge auger agitates the material until it is sucked into the pump.  It is transported by the pipeline to a dewatering system.  The dewatering is usually either a belt press or geosynthetic dewatering tube.  The filtrate is returned to the pond, and the sludge disposed of properly.

Sand dredging can be done within quarries or mines for mining or reclamation purposes.  Sand can be excavated with an excavator and stockpile easily as it dewaters rapidly.  Pumping sand with a dredge is an effective means to move sand and process it.  Sand pumps are made of specific metal to prevent wear.  Pipeline is usually high-density plastic to prevent wear as well. 

Fill divots with the sand provided up to the base of the existing soil, not to the top of the grass.  Be sure to smooth and compact it slightly with a step from a shoe, and have fun playing. 

If your pond discharge is not meeting the NPDES suspended sediment, turbidity, or other requirement, cleaning out the pond may be a solution.  Dredging can restore the capacity of the pond allowing fine silt to settle and treatment timeframes achieved.  NPDES permits are used in mining, construction, and farming.  Regardless, ponds are designed for capturing incoming silt and treating water effectively. 

Golf courses rely on irrigation.  Intakes allow water to be removed from pond and pumped throughtout the course to irrigate the greens and fairways.  A clogged intake can result from sediment or debris.  Often intakes can be backwashed to blow the sediment or debris away from the intake screen.  If this does not work, the screen may need cleaning by hand.  If you notice debris and sediment built up around the intake then dredging may be the best solution.