WPP categorizes external data into 3 general levels, which are related to the monitoring objectives (i.e., why the data were collected):
- Educational/Stewardship-level
- Screening level, and
- Regulatory/Assessment level.
While extremely important, data collected primarily for educational and/or stewardship purposes (level 1) generally does not meet the rigor (i.e., accuracy, precision, frequency, comparability, overall confidence, etc.) required for use in making water quality assessment decisions or in developing TMDLs. Although this type of data can be submitted, it is unlikely the data will be used for 305(b) or 303(d)-related decision making.
Screening-level data (level 2) are also very important and welcome, but generally fail to meet one or more WPP criteria required for direct use in water quality assessments or TMDLs. For example, Level 2 data may meet the data quality objectives in the submitter's Quality Assurance Project Plan (QAPP), but not those in the WPP's monitoring program QAPP approved by USEPA. Level 2 data may be used to direct future WPP sampling efforts and as supporting evidence.
Level 3 assessment-level data have been determined by MassDEP, based on the WPP's external data review procedures, to be directly usable for 305(b) and 303(d) decision-making. These data are considered scientifically sound and legally defensible, and are typically the result of extensive planning, attention to detail, relatively stringent data quality objectives, training, standard field and lab procedures, metadata collection, project organization, and data verification. Contingent upon WPP staff review and approval, quality-controlled data can help determine if a waterbody is meeting water quality standards or is impaired.
All external data submitted electronically are reviewed using a defined and consistent procedure. Use of WPP's data submittal template is the preferred format for external data submittals. Once data are received by WPP, a standard data review spreadsheet is used to facilitate and document the review. NOTE: QAPP approval, submittal of the data integrity statement and/or submittal of monitoring data does not guarantee that the data will be used by the WPP in its CWA 305(b) use assessment decisions.