How Can Machine Shops Reduce Water and Sewer Costs?

Published September 2, 2026. Last updated September 7, 2026.

Where Water and Sewer Costs Actually Come From

Machine shops pay for water twice: once to bring it in as fresh water for coolant makeup, washing, and process use, and again to send it out as wastewater, either through metered sewer discharge or hauled disposal when the discharge doesn’t meet POTW discharge compliance limits.

Coolant that’s dumped rather than recycled, rinse water from parts washing, and wastewater from any wet process all add to both sides of that cost. In many municipalities, sewer surcharges for industrial discharge scale with contaminant load, not just volume, so untreated or poorly treated wastewater can cost significantly more to discharge than clean water.

Reduce, Then Treat

The most direct way to cut water and sewer costs is to reduce the volume of wastewater generated in the first place, largely by recycling coolant rather than dumping it. A coolant recycling system that filters and maintains coolant on an ongoing basis extends the life of each batch, meaning less spent coolant needs to be treated or hauled away, and less fresh water and concentrate needs to be purchased to replace it.

This doesn’t eliminate the need for wastewater treatment; some water will always need to be discharged or evaporated. But it shrinks the volume that treatment has to handle, which lowers the cost of whatever treatment system follows.

What Industrial Wastewater Treatment Systems Actually Do

For water that does need to be treated before reuse or discharge, industrial wastewater treatment equipment typically combines several stages: physical or chemical separation to remove oils, solids, and metals; pH adjustment to bring water within POTW discharge compliance limits before it’s released to sewer; and, where a shop wants to reuse water rather than discharge it, a polishing step like reverse osmosis systems to produce water clean enough to put back into the process.

Reverse osmosis systems, in particular, can turn wastewater into a source of reusable process water, directly cutting the fresh water a shop needs to purchase, rather than just treating water to meet a discharge limit and letting it go.

On-Site Treatment vs. Hauling

Shops that don’t treat wastewater on-site are often paying to have it hauled off-site for treatment or disposal, a cost that scales directly with volume and typically includes both the hauling fee and a per-gallon treatment charge from the receiving facility.

Industrial wastewater treatment systems installed on-site convert that recurring hauling and disposal cost into a fixed capital investment plus lower ongoing operating cost. For shops generating consistent wastewater volume, that trade-off usually pays back over a defined period rather than remaining a permanent line-item expense.

Rebates, Surcharges, and Long-Term Cost Trends

Municipal sewer rates and industrial discharge surcharges have generally trended upward over time in most jurisdictions, particularly for dischargers with significant contaminant loads, meaning the cost of doing nothing tends to compound rather than remain flat. Some municipalities also offer rate reductions or rebate programs for industrial users who reduce discharge volume or contaminant load, which can further improve the payback case for on-site treatment.

Shops evaluating treatment equipment should confirm current local rate structures and any applicable industrial user surcharges directly with their municipal utility, since these vary significantly by jurisdiction and change over time.

Where Wastewater Treatment Fits with Overall Water Strategy

Water and sewer cost reduction tends to work best as a coordinated strategy rather than a single equipment purchase. Shops that pair coolant recycling upstream (reducing how much spent coolant and wastewater is generated in the first place) with the right treatment or reuse equipment downstream typically see a larger combined cost reduction than shops that address only one side.

It’s also worth mapping where water actually enters and leaves the facility before sizing anything, coolant makeup, parts washing, cooling tower blowdown, and general facility use can each contribute meaningfully to a shop’s total water and sewer bill, and the right fix looks different depending on which of those is the largest contributor.

Evaluating Treatment Options for a Machine Shop

The right system depends on wastewater volume, what’s actually in it (oils, metals, dissolved solids, coolant residue), and whether the shop’s goal is compliant discharge, water reuse, or both. Shops should look at wastewater treatment equipment manufacturers who can test the shop’s actual wastewater stream rather than sizing equipment off assumptions, since contaminant load varies significantly between a shop running mostly aluminum with soluble coolant versus one running mixed alloys with straight oils.

Systems should also be evaluated on how they handle the concentrated waste stream left behind after treatment, since that residual still needs a disposal path even after the bulk of the water is recovered or cleaned for discharge.

How PRAB Approaches Water and Sewer Cost Reduction

PRAB builds industrial process water and wastewater reuse and recycling systems, including reverse osmosis and pH adjustment equipment, and offers EVALED vacuum evaporation technology as an alternative or complementary option for shops looking to minimize the volume of wastewater that needs treatment or hauling in the first place.

Because reducing sewer costs often starts upstream of the treatment system, in how much coolant a shop is recycling versus dumping, PRAB typically evaluates wastewater treatment needs alongside a shop’s existing coolant recycling setup rather than as an isolated equipment decision, since improvements on one side change what the other side actually needs to handle.

De-Risking Your Investment

PRAB does more than build equipment. We engineer results.

Through our Demo Before You Buy™ and Materials Testing and Fluid Testing programs, we validate your application and define measurable performance specifications before you purchase.

Shops facing rising sewer surcharges are worth a direct look at both sides of the water balance before sizing new treatment equipment.