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quality solutions to solve the myriad and complicated problems faced by groundwater users

Penetrating Acid


ADPA - Dry Penetrating Acid

ADPA is a highly concentrated inhibited dry acid with a penetrant.  The penetrant speeds up acid penetration into formations and accumulations of scale and corrosive material on casings and screens.  It is a white, dry, non-volatile, inorganic acid in granular form.  This dry acid in inhibited for more concentrated use and is safe to use on all metal, rubber and plastic.


ADPA is for cleaning bore screens, casings, the gravel pack and the water bearing formation of deposits of mineral scale (calcium carbonate is the most common).  When dissolved in water, the acid penetrates the hardest encrustations in bores, converting these deposits into soluble salts which are easily pumped out.  The acid has a rapid attack rate on calcium and magnesium scales and also kills annoying algae slime found in some bores.  ADPA has excellent mud dispersing qualities.

ADPA has been found to be particularly useful in conjunction with a mechanical clean out.  It will permit a much faster and better job and will remove accumulations of plugging material which cannot be removed with mechanical tools alone.

Water bore production in sandstone and limestone formations or in highly calcareous sand and gravel can be increased by action of the acid in dissolving part of the formation.  The acid dissolves carbonates into harmless carbon dioxide.

To determine the cleaning effectiveness of ADPA, the bore capacity should be determined before and after the use of the acid.  Many older bores decrease in water flow due to the lowering of the water table.

ADPA offers essentially no hazard as far as accidental contact with dry skin is concerned.  It is free from the dangers of bottle breakage, liquid spillage and acid fumes.  It has an effective corrosion inhibitor and is safe to use on all metal encountered in water bores.  The first water pumped from a bore following ADPA treatment contains spent chemicals and should be pumped to waste until the water is clean.  The water is then safe to use for human and animal consumption.

ADPA is inexpensive to use with low handling and storage costs.  The amount required is based on varying dosages per litre of water in the bore casing and costs can easily be computed by referring to the Dosage Table.


•    Pour dry ADPA in the bore or mix the chemical with water and pour the solution down the casing or drop pipe.  ADPA should be added slowly.  Using 20 kg at a time, agitate the water to force the chemical out through the screen perforations, into the aquifer formation.
•    After pouring ADPA, agitate the bore water by pump surging, bailing, or by using compressed air.  For mechanical clean out water should be added to the bore to force the chemical out through the screen perforations and into the aquifer.  In a gravel packed bore, continuous circulation of the chemically treated water through the gravel wall will enhance results.
•    After 10 to 12 hours the spent acid and residues should be pumped or bailed out to waste until the bore water is clean and the pH level has returned to normal.

•    Deep bores with turbine  pumps installed should be agitated by surging (starting and stopping the pump) to raise the water almost to the ground level and then letting it drop back into the bore, being careful that none of the acid is pumped out of the bore.  Domestic bores with pumps installed with check or foot valves may be agitated by pumping water into an open tank and letting the water flow back into the bore through an opening at the top of the casing.  This should be done quickly to get a strong back flushing action.  Pump jacks will require replacement of leathers with Neoprene cuffs due to wetting action of the penetrant.


For a mechanical clean out with the pump pulled out, use 30 grams of ADPA per litre of bore water in the casing.  Using ADPA in combination with mechanical tools gives better and quicker cleaning.  For severe conditions use 60 grams of ADPA per litre of bore water in casing.


   Bore Diameter Litres of Water
per Metre in Bore
          ADPA per Metre
of Water in Bore
    30g 60g
2”    50.8 mm 2.0 .06kg .12 kg
4”     101.6 mm 8.1 .24 kg .48 kg
6”    152.4 mm 18.3 .55 kg 1.10 kgs
8”    203.2 mm 32.5 1.00 kg 2.0  kgs
10”    254.0 mm 50.7 1.50 kgs 3.0  kgs
12”    304.8 mm 73.0 2.20 kgs 4.40 kgs
14”    355.6 mm 99.4 3.0   kgs 6.0  kgs
16”    406.4 mm 129.8 3.80 kgs 7.60 kgs
18”    457.2 mm 164.3 4.90 kgs 9.80 kgs
20”    508.0 mm 202.8 6.0   kgs 12.0 kgs


ADPA is available in 20 kg pails..

per Metre in Bore