In the 60 m³ outdoor private pool, total trihalomethanes were measured at 8.6 μg/L. The only quantified THM was Bromoform.
Technical documentation
Technical White Paper on pool chlorination optimization
PoolDesign presents a technical white paper with monitoring results for disinfection by-products in two low-bather-load private pools where a stable low-dose TCCA protocol was applied. The document is not a general operating instruction, but a technical record of specific data, with clear limitations, methodology, and bibliographic documentation.
Relation to the summary page
This page is the technical documentation behind the summary presentation of chlorination optimization. It is intended mainly for technicians, engineers, facility managers, and partners who want to examine the data in detail.
For owners, management, or project stakeholders who first want a simpler view of the subject, PoolDesign provides a summary page.
View the summary pageWhat the white paper presents
The white paper examines pool chlorination as a matter of technical balance, not as a simple choice between higher or lower dosing. The analysis focuses on the relationship between disinfection, chlorination by-products, usage load, circulation, filtration, and real laboratory measurements.
The documentation is based on two low-bather-load private pools. One is a 60 m³ outdoor pool and the other is a 100 m³ indoor pool. In both cases, the results must be read within the limits of the specific operating conditions.
The purpose of the document is not to propose a general reduction of residual chlorine. Its purpose is to present what was observed, how it was evaluated, and which points require further confirmation before any wider application.
Key technical findings
The most important findings are summarized below. They concern the specific installations, the specific measurements, and the specific operating conditions.
Haloacetic acids were measurable and elevated compared with the indicative EPA limit for drinking water. The comparison is referenced only as a technical point of reference and not as a specific limit for pools.
The available microbiological indicators were not detected in the specific samples. The finding is positive for the specific conditions, but it does not constitute general evidence for operation at low FC.
In the 100 m³ indoor private pool, the transition from the previous NaOCl scheme to a controlled TCCA protocol was associated with a 96.7% reduction in introduced active chlorine in this specific installation.
The critical conclusion is that disinfection by-products must not be evaluated as a single category. In Pool A, THMs were low, while HAAs were measurable and require separate technical attention.
Scope of application and reading limits
The white paper concerns specific low-bather-load private pools. It does not directly apply to public, semi-public, or high-load installations without new technical evaluation, repeated measurements, and compliance checks against applicable requirements.
- The data comes from two pools in one geographic area.
- DBP chemical analysis was performed in one sampling event for Pool A.
- For Pool B, there are no THM/HAA measurements after the intervention.
- The presence of bromide ions was not measured directly and remains a hypothesis requiring confirmation.
- DOC/TOC or active HOCl were not measured directly.
- The results are not an instruction for general chlorine reduction.
These limitations do not reduce the value of the data. On the contrary, they define precisely how it should be read: as a technical observation of specific cases and as a basis for further investigation.
Why the distinction between THMs and HAAs matters
The evaluation of disinfection by-products cannot be based on a single indicator. THMs and HAAs behave differently in water and have different significance for technical monitoring.
In Pool A, THMs were low, but HAAs were measurable. This shows that an installation may present a positive picture in one indicator while still requiring attention in another.
For this reason, the white paper does not present the results as a simple success in “reducing by-products”. It presents them as a more complex technical finding: low THMs under specific conditions, but a need for separate monitoring of HAAs, bromides, organic load, and real disinfection capacity.
What the PDF includes
The full PDF includes the detailed technical documentation of the monitoring and evaluation. It is intended for technicians, engineers, facility managers, partners, and those who need a complete view of the data.
- executive summary and evidence level for the main claims,
- theoretical background on chlorine chemistry, CYA, and DBP formation,
- characteristics of the two pools and operating conditions,
- analytical methods and laboratory results,
- interpretation of THMs, HAAs, and microbiological indicators,
- study limitations and recommendations for further research,
- legal disclaimer and bibliography.
The PDF should be read as a technical evaluation document and not as a general pool operating instruction.
Technical documentation PDF
Download the full white paperThe PDF file includes the full methodology, results, limitations, and bibliography of the technical evaluation.
Download PDFWhen separate technical evaluation is required
Every pool has a different operating profile. Bather load, temperature, feed water quality, hydraulic behavior, filter condition, cover use, and compliance requirements can substantially change the result.
- public or semi-public pools,
- high-use hotel installations,
- indoor pools with increased air quality requirements,
- spas, whirlpools, or high-temperature tanks,
- pools with seawater or possible increased bromide presence,
- installations with frequent deviations in pH, CC, or microbiological indicators.
In these cases, the application of any protocol requires separate technical study, laboratory monitoring, and compliance with the applicable regulatory framework.
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