Greetings and salutations,

Waste water capture can be done easily with a gradall excavator or a tracked excavator with a ditching bucket to create an invert to allow the use of concrete sections cast for a concrete tunnel liner used in underground tunneling.

The sections are bolted together with a gasket membrane to seal them from allowing leaks and provide a perfect slope for water capture and containment to a concrete holding pond or a series of inverts to slow and stop the waste water and allow it to dry to collect the coal later when its dry.

The water can be reused to wash the inverts of the remaining coal dust as well if desired and the water can be reused of course.

The tiger in the bamboo is sizing the containment to stop and hold the waste water coming off the piles and inverts next to the piles. but as it will have a one percent or less down hill slope there will not be a wall of water going anywhere.

Many stock piles edges are simply lined with concrete channels to direct the waste water to an impoundment.

The stock pile floor is sloped to the channels as well.

It all depends on the acre inches of rainwater in a typical monsoon day-if there is a typical day.

Having a series of tunnel inverts set up like a wash boards ridges and declines before the entrance into a lined impoundment will slow the water down and allow the coal to settle somewhat as well.

Perhaps a semi permanent cover such as those made by (www.coverit.com) here in the states is a possibility? they come in a huge array of sizes/widths including huge systems for barns that are constructed of tubular steel with anchorages and a one piece roof from heavy water proof material. They would keep the coal dry and allow for stacking and reclaiming ease.

The only real neccesity would be to dig channels along the buried long edges of the roof fabric to allow water to escape away as it would not be polluted by the coal dust.

A slight modification of pile size may be all that is needed to utilize the above shed system as they can be made very long as desired with a little advance notification to the manufacturer to prepare the fabric roofs.

The (www.coverit.com) and (www.farmtek.com) sheds can be installed with unskilled labor and minimal hand tools also. with ground anchors or concrete anchors for the frame it self.

lzaharis ■

With a live stockyard in monsoon regions a cover is not practical, nor is attempting to collect run off in channels. What you need is a french drain with coal fill over a sand bed. Nowadays you'll need a membrane under the sand. Just over the sand you place fine coal and gradually build up to about 50mm in the top layer.

slurry gets slowed down by the top layer and can percolate down to the membrane which will direct it to your pond. Gravity sedimentation is not going to work on its own and you should consider some form of filter. Most of your suspended solids are captured in the french drains so you shouldn't need much of a filter although the feed pump will have to be adequate for the 10 year rainfall or whatever your local statutory regulations require. Good luck. ■