Superfund Information Systems: Site Profile

Superfund Site:

NYANZA CHEMICAL WASTE DUMP
ASHLAND, MA

Operable Units

Below, EPA has provided a list of the remedial actions selected pertaining to each operable unit.

EPA issues Records of Decision (RODs) to explain which cleanup methods will be used at Superfund National Priorities List sites. EPA has two primary documents that it may use to identify changes to the remedies selected in RODs. EPA uses a ROD Amendment when it needs to make a fundamental change to the remedy. EPA publishes an Explanation of Significant Differences (ESD) for significant changes.

During cleanup, complex sites may be divided into several distinct areas to make the response more efficient. These areas, called operable units (OUs), may address geographic areas, specific problems, or medium (e.g., groundwater, soil) where a specific action is required.

EPA is working to improve data quality. The information presented on this page is undergoing review for accuracy and completeness, and may be subject to change.

OU ID Name Decision Document Cleanup Technologies Selected
in the Decision Document
00 SITEWIDE No decision document
01 OU1 SOURCE CONTROL Record of Decision
September 04, 1985
Cap (engineered cap)
Cap (exsitu)
Consolidate (onsite)
Drainage/Erosion Control (ditch)
Excavation
Monitoring
01 OU1 SOURCE CONTROL Explanation of Significant Differences
September 21, 1992
Drainage/Erosion Control (other, NOS)
Revegetation
02 OU2 OFF-SITE GW Record of Decision
September 23, 1991
Air Stripping (P&T, exsitu)
Bioremediation (P&T, other, NOS, exsitu)
Discharge (surface water/NPDES discharge)
Extraction (recovery/vertical well)
Monitoring
Ultraviolet (UV) Oxidation (P&T, exsitu)
02 OU2 OFF-SITE GW Explanation of Significant Differences
September 29, 2006
Disposal (offsite)
Institutional Controls
Monitoring
Multi-phase Extraction (insitu)
Sampling
Sub-Slab Depressurization (SSD) (for VI mitigation)
03 OU3 WETLANDS AND DRAINAGE WAYS Record of Decision
March 30, 1993
Containment (other, NOS, onsite)
Dewatering
Dredging
Excavation
Institutional Controls
Monitoring
Residuals Treatment/Disposal (offsite)
Wetlands Replacement
04 OU4 SUDBURY RIVER Record of Decision
September 30, 2010
Enhanced Monitored Natural Recovery
Institutional Controls
Monitoring
Monitoring (fish tissue)
04 OU4 SUDBURY RIVER Explanation of Significant Differences
September 26, 2016
ESD/Amd - ARAR(s) Change
ESD/Amd - Remedy Component Removal
ESD/Amd - Significant Cost Change
Monitored Natural Recovery

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