D.C. Mun. Regs. r. 21-1828
When conducting the well development of a monitoring or observation well, a well owner shall allow groundwater flow conditions to equilibrate prior to purging the well.
If the well construction or well development methods introduced fluids, following the development of the well, a well owner shall allow the well to rest at least seven (7) days prior to purging and sampling.
Prior to sampling a monitoring or observation well, a person shall purge the well to facilitate collection of an accurate, reproducible, and representative groundwater sample, in accordance with appropriate EPA-approved sampling procedures.
An owner of a monitoring or observation well shall maintain the well to ensure that any testing procedures are appropriate for the intended use as stated on the well construction building permit and in the well construction work plan.
An owner of a monitoring or observation well shall comply with the data collection requirements of the District's Water Quality Monitoring Regulations in Chapter 19 (Water Quality Monitoring Regulations) of Title 21 DCMR if the results are to be submitted to the Department for regulatory and applicable decision-making purposes.
D.C. Mun. Regs. r. 21-1828