Current through Register Vol. 54, No. 44, November 2, 2024
(a)
Attainment of a standard shall be demonstrated with adherence to Data Quality
Objectives (DQO) and Data Quality Assessment (DQA) processes as specified by
the EPA, as appropriate. Attainment of the Statewide health or site-specific
standard will apply to the vertical and horizontal extent of soil identified as
contaminated from the release of a regulated substance above the selected
standard and of groundwater at the point of compliance and beyond in a site
characterization. Attainment of the background standard will apply to the
vertical and horizontal extent of soil and water identified as contaminated
from the release across the site. Where multiple releases occur on a property
which produce distinctly separate zones of contamination, the characterization
and subsequent attainment demonstrations apply individually to the separate
zones.
(b) Demonstration of
attainment in a final report shall include the following:
(1) A demonstration that the analysis of the
data, through the application of statistical tests provided for in §
250.707 (relating to statistical
tests), indicates that the standard has been met.
(2) For groundwater, a demonstration of a
statistical time trend analysis, knowledge of the plume stability or other
acceptable method that shows contaminant concentration at the point of
compliance will not exceed the selected standard. A statistical analysis shall
be applied that indicates continued attainment of the standard.
(3) For the site-specific standard, the
following apply:
(i) If pathway elimination is
part of the remediation, it shall be demonstrated on the basis of either an
engineering or hydrogeologic analysis, or both, which includes fate and
transport analysis that some or all of the exposure pathways have been
eliminated.
(ii) If pathway
elimination is not part of the remediation or it cannot be demonstrated that
all pathways have been eliminated, it shall be demonstrated that the calculated
numerical site-specific standards for the remaining pathways have been attained
in accordance with paragraphs (1) and (2), using the procedures in §
250.707(c) and
(d), or that the risk level remaining at a
site does not exceed a risk level of 1 x 10-4 and a
hazard index of 1, provided for in the act. If separate phase liquids are
present, it shall also be demonstrated that calculated site-specific numeric
standards are attained within the soil and groundwater directly impacted by the
separate phase liquids when those numeric standards are associated with
exposure to separate phase liquids.
(4) For the background and Statewide health
standards, if separate phase liquids are present, attainment at the point of
compliance shall also be demonstrated within the soil and groundwater directly
impacted by separate phase liquids.
This section cited in 25 Pa. Code §
250.707 (relating to statistical
tests).
