Surface water samples are usually collected when data about ambient conditions are needed. Samples are collected using surface grabs or submersible pumps. Samples can be used for chemical analysis or toxicity testing. To obtain information about depth strata, or when contaminant concentrations are low and can be masked by sampling related contamination, other sampling techniques are used.
- Ultra-Clean Water Sampling- involves the use of peristaltic pumps and pre-cleaned Teflon® tubing. Samples are collected from a continuous stream pumped from the target depth. Special sample handling techniques are used to avoid sample contamination after collection.
- Water Column Studies – Water column profiles can be developed by collecting discrete samples from specific depth strata using a sample bottle (i.e., Alpha or Beta Sampler), or pumping water from specific strata using a peristaltic pump. Physical parameters (i.e., temperature, pH, conductivity, salinity) can also be collected at each sample point by attaching sensors to the sample bottle or pump intake.