Sample Documentation

Documentation is an integral part of any pretreatment program. The validity of the samples collected and the data obtained both in the field (e.g. pH and flow) and in the laboratory (i.e. chemical analyses) is ensured through documentation and record keeping. All the information documented must be complete and accurate. Failure to maintain records and documentation according to set procedures could result in these documents being deemed inadmissible as evidence in court. All field records containing data must be signed by the inspector at the time of collection, including all COC forms.

General Documentation Procedures

Since many sampling reports may be used in enforcement proceedings, the inspector must keep a precise record of all sample collection and data handling. The industrial facility or POTW’s Sampling and Quality Assurance Plan should specify that the following information must be documented in the field record:

• Unique sample or log number: All samples should be assigned a unique identification number. If there is a serial number on the transportation case, the inspector should add this number to their field records.
• Date and time of sample collection: The date and time of sample collection must be recorded. In the case of composite samples, the sequence of times and aliquot size should be noted.
• Source of sample (facility name and address): The name and address of the facility being sampled shall be recorded as well as a narrative description and/or diagram referring to the particular site where the sample was taken.
• Name of sampling personnel: The name(s) and person(s) taking the sample should be indicated. For a composite sample, the name(s) of the person(s) installing the sampler and the name(s) of the person(s) retrieving the sample should be included.
• Sample type: Each sample should indicate whether it is a grab or composite sample. If the sample is a composite, volume and frequency of individual samples should be noted.
• Preservation method: Any preservatives (including the amount) added to the sample should be recorded, including the preservative amount and the method of preservation (e.g. refrigeration).
• Analysis required: All parameters for which the sample should be analyzed shall be specified.
• Field analysis: Field measurements must be recorded at the time that the analysis is completed. Examples of analyses that should be conducted and recorded in the field include:pH, temperature, DO, residual chlorine, and sulfites. Field analyses should be treated the same as any other sample (i.e. the sampler must record the date of the sample, type of sample, name of the sampler, COC, etc.).
• Flow: If flow is measured at the time of the sampling, the flow measurement should be recorded. If the sample is to be used to determine compliance, flow must be measured.
• Production rates: Information on products manufactured and production rates should be included since many effluent limitations are based on production rates.
• Date, time, and documentation of sample shipment: The shipment method (e.g. air or rail) as well as the shipping papers or manifest number should be recorded.
• Comments: This refers to all relevant information pertaining to the sample or the sampling site. Such comments include the condition of the sample site, observed characteristics of the sample, environmental conditions that may affect the sample, and problems encountered in sampling.

Each of these items should be recorded by the facility/POTW inspector when conducting site sampling, but this information should also be kept by the industrial user when it conducts its required self‐monitoring. This information should be available for review by the facility/POTW when conducting an on‐site inspection or sampling visit.

COC Procedures

Once an appropriate sample has been obtained and the sample collection methods are properly documented, a written record of the possession of that sample should be made. “COC” refers to the documented account of changes in possession that occur for a particular sample or set of samples (see Section 4.5.11 for a definition of “custody”). To ensure that all necessary information is documented, a COC form should be developed by the POTW.

COC procedures are a critical aspect in monitoring industrial users, and these procedures should be incorporated into the POTW’s Sampling and Quality Assurance Plan. The COC record allows an accurate step‐by‐step recreation of the sample path, from its origin through its final analysis in the laboratory. Every sample needs to be accompanied by a COC form that is properly signed and transferred to each person in the chain, from the original sampler to the final person involved in analyzing the sample. Since it is impossible to predict which violations will require legal action, it should be assumed that all data generated from sampling will be used in court. If a case ultimately goes to trial, the integrity of the data must be established. The sampling results will only be admissible in court if POTW personnel can prove that a sample has been properly collected, preserved, and analyzed, and has not been tampered with or mishandled.

The information that should be addressed in a COC form includes the following:

• Name of the person collecting the sample
• Sample identification number(s)
• Sample location
• Date and time of sample collection
• Parameters to be analyzed
• Container type(s) used
• Preservation method(s)
• Type of sample collected (i.e. grab, composite) for each pollutant to be analyzed
• Results of any analysis performed in the field (e.g. pH and temperature)
• Name(s), signature(s), dates, and times of all persons handling the samples in the field and in the laboratory

Note: Laboratories often have separate COC procedures, so the COC used in the field may end once the sample reaches the laboratory.

An example of a COC form used by POTWs is shown in Section D.1. All personnel handling the sample should receive a copy of the COC form showing the path of the sample from field to laboratory. All sample shipments must be accompanied by the COC record, while a copy of these forms should be retained by the originator. In addition, all receipts associated with the shipment should be retained. Carriers typically will not sign for samples; therefore, seals must be used to verify that tampering has not occurred during shipment.

When transferring possession of samples, the transferee must sign and record the date and time on the COC record. In general, custody transfers are made for each sample, although samples may be transferred as a group, if desired. Each person who takes custody must fill in the appropriate section of the COC record. Finally, the person or group at the POTW responsible for permitting, and/or compliance and enforcement, should receive a copy of the completed COC form.

COC records are crucial if the analytical data are to be used in an enforcement proceeding because they allow such data to be introduced as evidence without testimony of the persons who made the record. Therefore, it is important that all COC records be complete and accurate. To maintain the sample’s integrity, COC records must show that the sample was properly collected, preserved, and analyzed, and was not tampered with during shipment. COC records also show that samples were received and analyzed in accordance with method requirements. Therefore, all compliance samples taken at an industrial user should follow COC procedures.