Groundwater Treatment

Dissolved iron (Fe²⁺) and manganese (Mn²⁺) are among the most widespread groundwater quality issues globally. While secondary (aesthetic) maximum contaminant levels are set at 0.3 mg/L for iron and 0.05 mg/L for manganese, even lower concentrations can cause discolored water, staining of fixtures and laundry, metallic taste, and buildup in distribution pipes that reduces capacity and pressure over time.

The standard treatment approach involves oxidation followed by filtration. Aeration, chlorination, or dosing of potassium permanganate (KMnO₄) converts soluble ferrous iron to insoluble ferric hydroxide (Fe(OH)₃) and soluble manganese to manganese dioxide (MnO₂), which can then be removed by greensand or multimedia filtration. 

Milton Roy metering pumps provide the dosing accuracy and chemical resistance needed to inject oxidants — including sodium hypochlorite, potassium permanganate, and hydrogen peroxide — at precisely controlled rates that respond to variable raw water quality conditions. Flow-proportional dosing ensures that chemical consumption is optimized and residual oxidant levels remain within acceptable limits.

Arsenic contamination of groundwater is a critical public health concern in many regions worldwide. The WHO guideline and most national standards set the maximum allowable arsenic concentration at 10 µg/L. Treatment typically involves oxidation of arsenite (As³⁺) to arsenate (As⁵⁺) using chlorine or potassium permanganate, followed by co-precipitation with ferric chloride or ferric sulfate and removal through coagulation, flocculation, and filtration. Accurate metering of both the oxidant and the ferric coagulant is essential to achieve consistent arsenic removal below regulatory limits. 

Milton Roy hydraulic diaphragm (HAD) and mechanically actuated diaphragm (MAD) pumps are proven in these critical applications, delivering the precision, repeatability, and long-term reliability that arsenic treatment demands.

Hydrogen sulfide (H₂S) in groundwater produces the characteristic "rotten egg" odor that makes water aesthetically unacceptable, even at very low concentrations. Beyond odor, H₂S is corrosive to metal piping and can interfere with other treatment processes. Removal is typically achieved through aeration, chlorination, or dosing of potassium permanganate. 

Milton Roy metering pumps handle all of these oxidizing agents reliably, ensuring rapid and complete H₂S neutralization before the water enters the distribution system.

Groundwater pH can vary significantly depending on geology, ranging from acidic conditions in granitic or volcanic aquifers to alkaline conditions in limestone formations. Acidic groundwater is aggressive and can corrode metal and concrete pipes, leaching lead and copper into the distribution system. Alkaline groundwater can promote scaling and reduce the effectiveness of disinfection. Precise dosing of lime, sodium hydroxide, soda ash, or carbon dioxide allows operators to adjust pH to optimal levels for both treatment performance and distribution system protection. 

Milton Roy pumps deliver stable, accurate pH correction dosing even when handling aggressive and abrasive chemicals like lime slurry.