E. coli counts measurement context
An E. coli count gives the number of E. coli in a measured volume of water, not only whether E. coli is present. E. coli lives in the intestines of people and warm-blooded animals, so finding it points to fecal contamination. E. coli counts are commonly expressed per 100 mL of water, as colony-forming units (CFU) or as a most probable number (MPN), depending on the counting technique. Numeric E. coli limits appear in recreational water, surface water and discharge permits. Other indicator organisms
Plan collection and receipt together
Define the organism or indicator, test portion and enumeration or presence/absence question. Use the assigned bottle and collection instructions and coordinate delivery around the method requirements.
Include the complete project requirement
Provide the matrix, target analytes, required method, fraction, units and reporting limits. Include the permit or monitoring instructions where results will support a regulatory submission. Naming this method does not establish blanket compliance eligibility.
Resolve collection before sampling
Use the bottle, preservation and delivery instructions assigned to the agreed scope. Identify each location and collection time, and document any deviation. The final analytical plan must fit the submitted material and its intended use.
Related testing & guidance
Technical & service references
Vanguard service detailsSource review: November 8, 2026. The agreed method and project scope govern the testing.