How do operators know whether H2S chemical dosing is working?

Agree baseline and trial measurements at relevant locations, verify delivered dose and compare similar network conditions and travel times. Review downstream response and operating effort against defined treatment objectives. A single low gas reading does not prove sustained performance, complete sulphide removal or worker exposure compliance.

Which measurements may be reviewed?

Depending on the site, the review can consider H₂S peaks and percentiles, ORP, pH, oxygen, residuals and relevant complaint records.

Can you review performance with chemistry from another supplier?

Yes. Performance optimisation and reporting can be scoped independently of chemical supply, using agreed monitoring, network and dosing data.

Does a process gas logger establish worker exposure compliance?

No. Process monitoring is not personal exposure monitoring and does not establish occupational exposure compliance.

Sewer monitoring

H₂S monitoring & dosing performance optimisation

Use network and operating evidence to assess H₂S performance, identify where conditions shift and refine the dosing programme against agreed measures. The review can assess existing chemistry regardless of supplier.

Request a quote Frequently asked questions

Who this is for

Wastewater operations managers and sewer process engineers

Your operating priority

Distinguish real H₂S treatment performance from changes in flow, weather or sensor conditions, without tying the review to a chemical supplier.

Before you specify or buy

Agree baseline and trial windows, monitoring locations, calibration checks and dose records before interpreting a treatment comparison. The existing chemistry may be supplied by Critical Elixirs or another provider.

What is covered

Review peaks and percentiles alongside ORP, pH, oxygen and residual data where available.
Include complaints or operational observations where relevant to the assessment.
Relate monitoring locations and times to network conditions and actual dose delivery; the chemical supplier does not determine whether the service can be scoped.
Agree baseline, monitoring period and reporting basis before interpreting changes.

What we will ask you

Monitoring records and sensor locations
Dose points, settings and network operating conditions
Relevant complaints, maintenance events and intended measures

This page is information only. Pricing, availability and specifications are provided through an enquiry.

Straight answers

Frequently asked questions

How do operators know whether H2S chemical dosing is working?: Agree baseline and trial measurements at relevant locations, verify delivered dose and compare similar network conditions and travel times. Review downstream response and operating effort against defined treatment objectives. A single low gas reading does not prove sustained performance, complete sulphide removal or worker exposure compliance.
Which measurements may be reviewed?: Depending on the site, the review can consider H₂S peaks and percentiles, ORP, pH, oxygen, residuals and relevant complaint records.
Can you review performance with chemistry from another supplier?: Yes. Performance optimisation and reporting can be scoped independently of chemical supply, using agreed monitoring, network and dosing data.
Does a process gas logger establish worker exposure compliance?: No. Process monitoring is not personal exposure monitoring and does not establish occupational exposure compliance.

H₂S, methyl mercaptan, pH, ORP and SRB testing

H₂S and methyl mercaptan are different sulphur compounds; an instrument reading for one must not be presented as a result for the other. pH and oxidation-reduction potential (ORP) provide water-condition context alongside appropriate gas and liquid sampling. Where sulphate-reducing bacteria (SRB) testing is included in the scope, agree the sample method and laboratory interpretation. ORP or a photograph alone does not identify or quantify SRB. Conductivity and total dissolved solids (TDS) information can add water-quality context, but a conductivity-derived TDS estimate is not a direct H₂S or SRB test.

Compare dosing performance using an agreed baseline, monitoring locations, operating conditions and calibrated instruments. The photographs below document field activity, not a before-and-after treatment result or proof of exposure compliance.

Field equipment and testing

Real sampling, measurement and dosing equipment. Individual photos are not a controlled performance comparison; interpretation requires the sampling context, method and calibration records.

Methyl mercaptan field measurement. A spot reading is not a worker-exposure assessment or a treatment comparison.
pH and oxidation-reduction potential (ORP) measurements help interpret water conditions alongside sampling and calibration records.
Site sampling and water-quality measurement. Sample location, handling and instrument checks affect interpretation.
A field dosing installation. Equipment configuration and operating settings are confirmed against the duty.
Field pH, ORP and dissolved-oxygen measurements. ORP is not a direct SRB count or proof of sulphide removal.
Field pH measurement. Calibration, sample conditions and treatment objectives are needed to interpret the reading.