Wastewater Compliance Sampling

EST collects more wastewater samples for permit compliance than any other environmental sampling company in the Northeast. Our clients include leading manufacturing and industrial facilities, hospitals, universities, and biotech firms. Our services include the collection of representative composite samples (time-weighted and flow-weighted) and grab samples, preservation in accordance with 40 CFR part 136, chain of custody, and coordination of laboratory analytical services. In addition, EST maintains an extensive inventory of automatic samplers and related field instruments to assist our clients with staying in compliance with their industrial discharge permit requirements.

If you are an environmental manager with limited time and resources, just send EST a copy of your discharge permit and we will handle all of the sampling and analytical work associated with your permit.


Common Wastewater Sampling FAQs

What is the difference between a composite and a grab sample?

Wastewater sampling is typically performed by one of two methods: composite sampling or grab sampling.

Grab sampling is a simple method of collecting discharge at one time.  That said, the data is representative of the specific point in time that the sample was collected.

Composite sampling consists of collecting numerous individual aliquots over a period of time.  The discharge being sampled is collected in a common container over the sampling period, usually 24 hours.  This method’s data is representative of the average performance of a wastewater discharge during the collection period.

What is a Time Weighted Composite vs a Flow Proportional Composite?
There are two basic types of composite methods in water sampling: time-weighted and flow-weighted.

When performing a time-weighted composite, samples of equal volumes are taken at constant intervals during the sampling period. For example, four aliquots are taken every six hours to create a 24-hour composite sample.

In flow-weighted sampling, samples are collected proportionally to the effluent flow/volume during the sampling period. Meaning aliquots are taken when fixed amounts of effluent have passed through the sampling point.  For example, one aliquot is collected every five gallons.

What is included with EST’s sampling costs?

Our costs include providing all labor, equipment and materials necessary to collect samples, proper field screening and preservation, transporting of samples to a certified laboratory, chain of custody documentation, and that all personnel are OSHA-40 certified.

Contact us today for a formal proposal.

Can EST collect AND analyze my samples?

EST does not perform laboratory analyses in-house but we work with and subcontract dozens of MA DEP and NJ DEP certified laboratories for our wastewater and groundwater clients.  Just let us know if you have a preferred laboratory or we can recommend one that will suit your needs.

How long will it take to receive my analytical results?

Once relinquished to the laboratory, reports are received within 5-10 business days.  If you need your results sooner, we can easily request a rush turnaround with the laboratory for an additional fee.

How do I schedule my compliance sampling?

At EST, we want your wastewater compliance scheduling to be as easy as possible.  Contact our Client Services department to schedule your event each round or we can set up your site on an automatic sampling schedule.  Your schedule will contain confirmed dates for the entire year and you will also receive an email reminder two business days prior to sampling.  If the dates provided ever present a problem, just notify our CS Department and they will be happy to reschedule as needed.

New England Office

51 Fremont Street Needham, MA 02494

Mid-Atlantic Office

127-G Gaither Drive Mount Laurel, NJ 08054