Landfill Leachate Remediation Project - Armstrong, BC
Findings
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Landfill Site 1
A landfill site can be a place of unknowns and untimely incidents. Anticipation is required regarding other activities by other contractors. Careful planning can still result to the negative in the best of intentions.
Responsible control with human hands does not allow too much automation. Automation will not detect a possible spill or may shut down unnecessarily causing time loss and valuable data corruption. This is a “hands on” operation to be done safely. A good filter system must be installed between pump exit and ahead of character irrigation systems. The character irrigation system must be monitored on-going for plugging from algae growth at the spitter exit point. Pumping and irrigation must be done with a good washable filter system.
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The intake must be a spring loaded foot valve floating about 12 inches below the surface for best quality product. Spring start-up may require pump disassembly, cleaning and reassembly. That can happen any time for that matter. “Character” irrigation, or the individual tree sprayer “spot spitter” worked best over five years. For improved broadcast of spray a new configuration is not needed for the 6th season.
Hybrid poplars can be grown with this leachate. And they can be grown without or certainly minimal potable water. Rain and snow provide enough freshet for this area situation.
We realized a good growth rate; about 90% of a usual growth rate in a usual plantation case.
The correct variety for this scenario showed itself via data and observation. Further to this discussion, wood fiber analysis, (Which I am told should have been done more often), shows big uptake of NA, (sodium). That is partial explanation for the high conductivity rates experienced throughout.
The realized wood fiber production from 250 trees after completed growth over 5 years is 872 cubic feet or 25 cubic meters including the trunk only.
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But fiber mass with branches included will be approximately 50 cubic meters. The roots are fiber mass not figured in. This is done on approximately 1.25 acres. .25 acres is a buffer to a neighbor.
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Weeding close to the trees is best done with a favorite hoe and muscle power. It is an all the time activity. This takes away any question that may crop up by using herbicide. The equipment must be visible or free of weeds and therefore fully accessible for repair and un-plugs. Roto tilling or aeration and weeding between rows is done to a maximum 4 times per season.
The garbage dump liquid effluent is not that toxic, although obviously, certainly best kept out of the food chain. A fresh water supply must be on site for safety procedures. I personally have suffered no observable health effects. Hand washing, careful handling and common sense are the order of the day. Water application can be done without touching any contaminated parts.
The best way to determine how much effluent to apply on a given day is a common sense approach. Weather plays a very integral part of the equation. True scientific approach to soil moisture content is too costly and best left to a laboratory science lab situation in my opinion. There is some sense of balancing the effluent availability, although, after five years that has not been an issue. The “Grow Point” sensor device showed fairly constant moisture content at 1 ft, 2 ft, 3ft, 4ft and 5 ft distances away from the tree. The numbers in average were at 1 ft – 9.3, 2ft – 10.2, 3ft – 6.35, 4ft – 5.45, 5ft – 6.68 respectively, which is an overall average of 7.6% and was measured before watering. This was watering at a rate of 20 gallons of leachate and 5 gallons of potable per day per tree. In the center (or 8 feet away) of the rising 5 plantation showed 5.3% moisture content.
In early July, the temperatures were at a fairly steady average of 30 degrees daily. I took 11 readings at a tree I have chosen to monitor consistently for soil moisture content. After watering 28 gallons of leachate and 6 gallons of potable, I found an average of 9.9% moisture content. Next morning Jul 12th, before watering, I found an average on the same spot of 7.12 %. That represents a 2.78 % moisture content utilized between watering. The irrigation rate was 28 gallons of leachate and 6 gallons of potable per tree.
August 1st, extreme heat seemed to be the norm. I took 11 readings again with the ESI instrument at the same study tree. After 20 gallons of leachate and 5 gallons of potable (per tree) the readings were in average 9.7 % the readings changed surprisingly little 5 feet from the tree as opposed to 2 feet away from the tree.
Expensive, permanent moisture detection probes should have been installed from the outset for a more scientific approach to watering rates. But that common sense of considering weather conditions and etcetera is still a valid method.
A pleasant surprise to me shows moisture quite evenly spread on the plantation. Readings by two separate types of equipment and two different people showed in the center of the rows to be only 2 points below the averages outside a 5 foot radius of each tree.
A full canopy now exists on this site. I believe the trees are consuming appropriately for their size in spite of the canopy. (The sun cannot dry the ground as readily as without a canopy). Some of last year’s numbers for consumption were close to numbers now, although not as prolonged.
Very noticeable is the fact that branches are right down to pruning height. The trees are really healthy, so this is a very full canopy, not a lot of sun can get through.
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About 30,000 gallons US leachate (on average), can be pumped between filter washing. The disk filter removable tubes work well in this application. The safety factor with this configuration is easy to apply for personnel. Water quality is hardness extreme. Little black lumps form inside pipes.
The PH testing device must be re-calibrated often. Much of the data for PH levels is inaccurate. More expensive or scientific comprehensive type equipment is required.
Values are found for the trees as a necessary fund raiser to support the project, (which protects the environment). The project caused me to learn there are over 200 products derived from an entire tree. (Ethanol emerges as the most pertinent product as it is a much needed renewable energy source. Two hundred liters can be produced from one meter of hybrid poplar).
This is an alternative to allowing unabated pollution flow. In this instance we put the phyto installation nearby as opposed to atop the decommissioned area of the landfill site. The better situation for an installation would be atop a de-commissioned area.
This project is politically correct.