THE COST OF HAULING WATER, PART 2

Last time I looked at the cost of hauling liquid sludge.  This time I will look at hauling cake.

The table below shows the cost of hauling cake at $25 and $20 per wet ton.

TABLE 1
THE COST OF HAULING CAKE

CAKE SOLIDS	TONS WATER/TON SOLIDS	COST/DRY TON @ $25/WET TON	COST/DRY TON@ $20/WET TON
15%	5.6	$166	$133
20%	4	$125	$100
25%	3	$100	$80
30%	2.3	$83	$67
35%	1.8	$71	$57

You can see from this table and then comparing cake vs. liquid hauling costs that:

• cake hauling is less expensive than liquid hauling until you get the liquid solids up to 6% or more
• if liquid hauling is more expensive than 3 cents/gallon, cake hauling will be cheaper at any concentration
• You save a lot of money getting the cake colilds from 15% or 20%, but not so much from 30/5 to 35%

So, what keeps you from switching over to cake solids immediately?  The cost of the dewatering equipment.   I wont't go into the actual costs herede but you will need:

• The dewatering machine
• A polymer feed system
• A building for the dewaterng maching
• A conveyor
• A cake storage pad, preferably a COVERED storage pad
• A front end loader if you don't already have one to load the cake
• Utilities to the building.
• A mechanism to get the cake to the storage pad, either a conveyor (preferred) or a dump truck ( not preferred)
• If you are DIY on sludge hauling, you will need 30 cubic yard dump trailer(s) or lots of dump trucks.

You will have to do your own arithmetic.  Cake hauling prices range from less than $15/wet ton to over $25/wet ton depending upon location and competition

What kind of dewatering device?  Thats a whole other lecture.  Centrifuges make the dryest cake but may not be the most cost effective for you.  Rotary presses do well on some sludges and have some advantages on water use, odor and noise. Belt presses are less expensive than centrifuges, but the cake is usually wetter.  For the smallest operations, simple geotubes work best.  Hire me and I'l help you figure it out.