Operating Records, Logs & Documentation

Accurate records are a fundamental part of water and wastewater operation. Operators use records to demonstrate regulatory compliance, communicate between shifts, evaluate treatment performance, document maintenance, investigate problems, and show what actions were taken during abnormal conditions.

Good records should allow another qualified person to reconstruct what happened at the facility. A useful record identifies the condition observed, when it occurred, who made the observation, what action was taken, and what happened afterward.

Why Operating Records Matter

Operating records serve several purposes at the same time.

• They document compliance with permits and regulations.
• They support process-control decisions.
• They preserve information between shifts.
• They help identify long-term trends.
• They support troubleshooting.
• They document maintenance and equipment problems.
• They provide evidence of actions taken during emergencies.
• They help supervisors and regulators evaluate plant performance.

A plant can be operating well today and still need records from weeks or months earlier to understand a developing problem.

Operating Logs

An operating log is a chronological record of important plant conditions, observations, activities, and decisions.

A useful operator log may include:

• date and time;
• operator name or initials;
• flow rates;
• tank or reservoir levels;
• chemical-feed settings;
• disinfectant residuals;
• process readings;
• equipment status;
• alarms;
• maintenance activities;
• abnormal conditions;
• process adjustments;
• communications with supervisors, owners, laboratories, or DEP;
• important information for the next shift.

The exact content depends on the facility, but the log should capture information needed to understand system operation.

Record Facts, Not Vague Statements

Entries should be specific enough to be useful later.

For example, instead of writing:

Pump problem. Fixed.

a more useful entry would identify:

• which pump was affected;
• what problem was observed;
• when the problem began;
• what action was taken;
• whether the pump returned to service;
• whether additional maintenance is required.

Specific factual records are more useful than vague comments.

Record Information When It Happens

Operational information should be recorded as close to the time of the activity or observation as practical.

Waiting until the end of a long shift increases the risk of:

• forgetting details;
• entering the wrong time;
• confusing one event with another;
• omitting an important action.

Contemporaneous records are generally more reliable than entries reconstructed later from memory.

Date and Time Are Essential

Many operating events must be understood in sequence.

For this reason, records should clearly indicate the date and time when appropriate.

This allows operators to compare events such as:

• an alarm;
• a chemical-feed adjustment;
• a laboratory result;
• a pump failure;
• a high-flow event;
• a process response.

Without accurate time information, it may be difficult to determine cause and effect.

Identify Who Made the Entry

Records should identify the operator, analyst, sampler, or employee responsible for the recorded activity when appropriate.

This can be done through:

• full name;
• initials;
• electronic user identification;
• another approved traceable method.

The important principle is that the record can be connected to the person who performed or documented the activity.

Laboratory Records

Laboratory records document analytical results used for process control and regulatory monitoring.

DEP training materials identify analytical records as valuable tools for determining whether plant processes are working effectively.

Laboratory records commonly include:

• sample identification;
• sample location;
• collection date and time;
• analysis date and time;
• test method;
• analyst initials or name;
• instrument or equipment information where needed;
• analytical result;
• quality-control information;
• calculations;
• unusual observations.

Bench Sheets and Laboratory Notebooks

Analytical data may be recorded on laboratory bench sheets, laboratory notebooks, electronic systems, or other approved records.

DEP training guidance notes that laboratory notebooks often use bound and numbered pages so removal or alteration of pages is evident.

Whatever format is used, the record should preserve traceability and the original analytical information.

Quality-Control Records

Quality-control records help demonstrate that analytical results are reliable.

Depending on the method, QC records can include:

• calibration results;
• standards;
• blanks;
• duplicates;
• control samples;
• instrument checks;
• corrective actions.

Analytical results without supporting QC information may be difficult to defend if the accuracy of the data is questioned.

Sampling Records

Sampling records should show that required samples were collected correctly and at the required time and location.

A sampling log may include:

• sample date;
• sample time;
• sample location;
• sample type;
• sampler name or initials;
• preservation information;
• laboratory destination;
• chain-of-custody information where applicable;
• unusual conditions.

For regulatory samples, accurate documentation can help demonstrate that the monitoring requirement was satisfied.

Operational Process Records

Operators should maintain records that allow treatment performance to be evaluated over time.

Depending on the system, these may include:

• influent and effluent flow;
• pump run times;
• tank levels;
• chemical usage;
• chemical-feed rates;
• filter run times;
• turbidity;
• chlorine residual;
• pH;
• dissolved oxygen;
• settleability;
• sludge wasting;
• return activated sludge flow;
• pressure;
• other process-specific readings.

Records are especially useful when operators can compare process changes with resulting water-quality or treatment-performance changes.

Use Records to Identify Trends

A single operating value tells the operator what is happening at one moment. A series of records shows the direction in which the process is moving.

Trend review can identify:

• gradual loss of pump capacity;
• increasing chemical demand;
• declining filter performance;
• increasing sludge inventory;
• changing dissolved oxygen demand;
• seasonal flow changes;
• increasing equipment maintenance frequency.

Trend recognition allows corrective action before a serious failure occurs.

Maintenance Records

Maintenance records show what equipment was inspected, serviced, repaired, or replaced.

A useful maintenance record may include:

• equipment identification;
• date;
• problem reported;
• inspection findings;
• work performed;
• parts used;
• employee or contractor performing the work;
• equipment condition after repair;
• recommended follow-up.

Maintenance history can reveal recurring failures and help determine preventive-maintenance intervals.

Record Unusual Events

Normal operating values are important, but unusual events are often even more important to document.

Examples include:

• power failures;
• high-flow events;
• loss of disinfection;
• equipment failures;
• chemical spills;
• main breaks;
• sewer overflows;
• permit exceedances;
• alarm conditions;
• emergency repairs;
• communications with regulatory agencies.

The record should describe what happened and what actions were taken.

Document Process-Control Decisions

Important process adjustments should be recorded so operators can understand why plant conditions changed.

For example, an entry might document:

• the parameter that triggered concern;
• the adjustment made;
• the time of adjustment;
• the operator responsible;
• the follow-up reading;
• whether additional adjustment was necessary.

This allows later operators to evaluate whether the adjustment had the intended effect.

Shift Handoff Documentation

A shift change creates a risk that important operational information will be lost.

The outgoing operator should communicate significant items such as:

• equipment out of service;
• temporary operating conditions;
• abnormal laboratory results;
• pending samples;
• chemical deliveries;
• maintenance in progress;
• alarms;
• process changes;
• special monitoring requirements.

Written records support the verbal shift handoff and provide a permanent reference.

Correcting Paper Records

Errors in paper records should be corrected without destroying the original entry.

DEP laboratory training guidance recommends that an incorrect result be crossed out with a single line so the original entry remains readable.

The correction should then be entered clearly and identified by the person making the correction, typically with initials and, where appropriate, the date.

Do not erase the original value or use a correction method that makes the original entry impossible to read.

Why Erasing Is a Problem

A record should show what was originally entered and that a correction was later made.

If the original information disappears completely, a reviewer cannot determine:

• whether the change was legitimate;
• who made the change;
• when it was made;
• whether the record was altered to hide a problem.

Traceable corrections protect both the integrity of the record and the operator.

Electronic Records

Many systems now use electronic operating logs, laboratory information systems, SCADA historians, computerized maintenance systems, and electronic regulatory reporting.

Electronic records should preserve the same basic principles as paper records:

• accuracy;
• traceability;
• operator identification;
• date and time;
• protection against unauthorized alteration;
• appropriate backup;
• retrievability.

An electronic system should not allow important regulatory data to disappear simply because someone edits a value.

SCADA Data Are Not a Complete Operator Log

SCADA systems can automatically record values such as flow, pressure, tank level, alarms, and equipment status.

However, automated data may not explain:

• why an operator changed a setting;
• why equipment was placed out of service;
• what maintenance was performed;
• what discussion occurred with management or DEP;
• what unusual field condition was observed.

Operator notes often provide context that automated data cannot provide by itself.

Records Must Be Legible and Understandable

Paper records should be legible. Electronic entries should use clear terminology.

A record that only the person who wrote it can understand has limited value.

Avoid unexplained abbreviations, unclear symbols, and incomplete comments unless they are part of an established facility system understood by all users.

Do Not Record Information You Did Not Observe

An operator should not sign, initial, or enter a value as though personally observed if the operator did not actually perform or verify the activity.

If information is received from another employee, laboratory, instrument, or outside source, the record should make that clear when relevant.

Traceability is more important than making the record appear complete.

Never Falsify Operating Records

Falsifying operating, sampling, monitoring, certification, or laboratory records is a serious matter.

Pennsylvania DEP identifies falsification of sample results, monitoring records, and other records relating to system operation as operator misconduct.

Possible consequences can include:

• regulatory enforcement;
• operator certification suspension;
• operator certification modification;
• operator certification revocation;
• other legal consequences.

Operators should report actual results and actual conditions, even when the information shows poor plant performance or noncompliance.

Do Not Backfill Missing Data

If a required reading was missed, do not invent a value later to make the log appear complete.

Instead:

• identify that the measurement was missed;
• record the reason when known;
• notify the appropriate supervisor when required;
• determine whether the missed measurement creates a compliance issue;
• take corrective action to prevent recurrence.

An honest record of a missed reading is preferable to a false value.

Regulatory Records

Water and wastewater systems maintain records required by permits and regulations.

Examples can include:

• laboratory reports;
• sampling records;
• DMRs;
• public notifications;
• Consumer Confidence Reports;
• operational monitoring;
• maintenance and inspection records;
• chemical records;
• operator reports;
• incident and noncompliance reports.

Different record types may have different retention periods.

Know the Retention Requirement

Do not assume that every record can be discarded after the same length of time.

Retention requirements depend on the type of record and the applicable drinking water regulation, wastewater permit, laboratory requirement, or other rule.

Facilities should maintain a retention schedule identifying:

• record type;
• required retention period;
• storage location;
• responsible person;
• approved disposal procedure.

Records Must Be Retrievable

Keeping a record is not useful if it cannot be found when needed.

A good filing system allows staff to locate records by:

• date;
• process;
• equipment;
• sample location;
• permit reporting period;
• other logical category.

Electronic records should be backed up and protected from accidental deletion or unauthorized changes.

Records Support Troubleshooting

When a process problem occurs, operators should compare present conditions with historical records.

For example, wastewater operators investigating poor settling might review:

• MLSS;
• SVI;
• dissolved oxygen;
• RAS rate;
• wasting rate;
• influent loading;
• microscopic observations;
• recent process adjustments.

A drinking water operator investigating increased turbidity might review:

• source-water turbidity;
• chemical dose;
• pH;
• filter loading;
• filter run time;
• backwash history;
• finished-water turbidity.

Historical records convert troubleshooting from guesswork into evidence-based analysis.

Records Support Preventive Maintenance

Maintenance records can show whether an equipment problem is becoming more frequent.

Examples include:

• a pump requiring seals more often;
• a bearing showing repeated vibration problems;
• a valve repeatedly failing to close;
• a chemical pump losing calibration;
• a filter requiring cleaning at shorter intervals.

These trends can indicate that repair, replacement, or a change in maintenance practice is needed.

Records During Emergencies

During an emergency, operators should first protect people, public health, the environment, and the treatment process.

Once immediate safety needs are controlled, accurate records should document:

• time the event was discovered;
• initial conditions;
• notifications made;
• actions taken;
• equipment status;
• sampling performed;
• time conditions returned to normal;
• follow-up activities.

This information can later support regulatory reporting, investigation, and corrective action.

Use Standardized Forms Where Practical

Standard forms can reduce omissions by reminding operators which information must be recorded.

Examples include:

• daily operating sheets;
• laboratory bench sheets;
• sampling logs;
• maintenance work orders;
• inspection checklists;
• chemical delivery forms;
• incident reports;
• shift handoff forms.

A form should support good documentation rather than encourage operators to fill boxes without evaluating the information.

Common Recordkeeping Mistakes

• Recording values from memory long after the observation.
• Leaving entries without a date or time.
• Failing to identify who performed the activity.
• Using vague comments such as "everything normal."
• Erasing incorrect laboratory values.
• Using correction fluid to hide the original entry.
• Failing to record an important process adjustment.
• Entering values that were never measured.
• Copying yesterday's readings into today's log.
• Omitting an unfavorable result.
• Failing to document maintenance or equipment failures.
• Relying on SCADA data without recording operator decisions.
• Discarding records without checking retention requirements.
• Allowing electronic records to be changed without traceability.
• Using records only for compliance instead of also using them for process control and troubleshooting.

A Practical Recordkeeping Routine

1. Record important information when the observation or activity occurs.
2. Include the correct date and time.
3. Identify the operator, analyst, or sampler.
4. Use the correct units.
5. Record actual measured values.
6. Document abnormal conditions and important process changes.
7. Record maintenance and equipment status.
8. Correct errors without hiding the original entry.
9. Review logs during shift handoff.
10. Compare current readings with historical trends.
11. Store records in an organized and retrievable system.
12. Protect electronic records and maintain backups.
13. Follow the applicable retention requirements.
14. Never falsify, invent, or conceal operational data.

What to Remember for the Exam

• Operating records document compliance, process performance, maintenance, decisions, and unusual events.
• Good records should allow another qualified person to understand what happened.
• Record information as close to the time of the activity as practical.
• Important records should include date, time, and operator or analyst identification when applicable.
• Sampling records should identify the sample location and collection information.
• Laboratory records should preserve analytical and quality-control information.
• Operational records help identify trends and troubleshoot treatment problems.
• Important process-control adjustments should be documented.
• Shift logs help transfer information between operators.
• Paper-record errors should generally be crossed out with a single line so the original entry remains readable.
• Corrections should be traceable to the person making them.
• Do not erase, conceal, or invent operating data.
• SCADA records are useful but may not explain operator decisions or unusual conditions.
• Electronic records should be protected against unauthorized alteration and loss.
• Different regulatory records can have different retention periods.
• Records should be organized so they can be retrieved when needed.
• Falsification of operating or monitoring records can lead to serious regulatory and operator-certification consequences.