M4L9Field_Notebook

Module IV

Lesson Nine: Stormwater Sampling Procedures

Recording Field Notebook

It is required to record the following information into the field notebook for stormwater samples. They are:

Time of the rainfall began
Sampling locations
Date of the sampling
Time of the sampling
Describe the way samples are collected, e.g., took samples from ditch/pipe/manhole by hand/bottle on a pole, etc.
Name of the sampler(s)
Number, types (parameters) of samples collected
Field measurement results, such as pH, temperature
Unusual circumstances that may affect the sample results

The field notebook should be written with waterproof ink. If there is any mistake in writing data, it should be crossed out rather than erased or whited out. Number the pages of the field book consecutively. Do not rip out pages from the field notebook to ensure that the bound field book is a complete record of sampling procedures.

It is not required but suggested by the general permit to record the following information for each storm event sampled:

Number of dry days before the day the sample was collected, or a statement that there was at least one day of no greater than trace precipitation before sampling
Inches of rainfall during a 24-hour period of the storm event
Date and time of the sampling
Date and time the rainfall began
Date and time the discharge began at the sampling site
Duration of the storm in hours

The information recorded above will help permittees to document whether they meet the recommended criteria for stormwater sampling specified in the general permit or not. When the criteria cannot be met, it is required by the general permit that the permittee must still collect and submit stormwater sampling results, and must include an explanation with the monitoring report identifying what recommended criteria were not met and why.