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Site Report: UNOCAL Ammonia Plant

Site Name: UNOCAL Ammonia Plant
Address: 47901 Kenai Spur Highway, Mile 21 North Kenai Road, Nikiski, AK 99635
File Number: 2323.38.032
Hazard ID: 1008
Status: Active
Staff: Peter Campbell, 9072623412 peter.campbell@alaska.gov
Latitude: 60.675000
Longitude: -151.379167
Horizontal Datum:NAD83

We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.

Problems/Comments

Seal on lubricating system compressor failed causing oil to be released. Four hundred gallons were spilled. A dike was built around the spill and a vacuum truck picked up a large portion of oil. Gravel was excavated and stockpiled on a concrete pad until approval was received to dispose of it. Searched for the file on 5-17-2006 and was unable to locate file. This site is being worked as the UNOCAL Ammonia Urea Plant, File Number 2323.38.032, Reckey:1988230918305. Information was obtained from the Kenai district office contaminated sites follow-up report dated 9/25/1990.

Action Information

Action Date Action Description DEC Staff
6/4/1991 Site Added to Database Petroleum contaminant. Former Staff
3/4/1993 Site Ranked Using the AHRM Site Ranked. Former Staff
9/30/1994 Update or Other Action (Old R:Base Action Code = SI - Site Investigation). Monica English
5/18/2006 Update or Other Action File number 2323.38.032 assigned and entered into the CS DB. Alyce Hughey
6/14/2006 GIS Position Updated Using the Facility Map in the file, in conjunction with the KPB Parcel Lookup, and TopoZone Pro, entered the coordinates for this site. Metadata includes No Topo Basemap, TopoZone Pro Street Maps, Black and White Aerail Photo, on a Medium Size Map, View Scale 1:10,000, Coordinate Datum NAD83. High degree of confidence in accuracy of location. Alyce Hughey
5/23/2008 Update or Other Action Ranked the site using the ETM. Minimal site information available for this release, intent is to keep the spill file open and address cleanup actions at the time of facility closure. Don Fritz
5/23/2008 Exposure Tracking Model Ranking Initial ranking with ETM completed. Don Fritz
11/3/2011 Update or Other Action This site is being worked as the UNOCAL/Agrium Ammonia Urea Plant, and contamination will be addressed upon plant closure. A groundwater monitoring plan has been developed. Northern part of the facility is being removed and contaminated areas will be addressed at that time, and a background metal sampling has been approved on March 9, 2011. Alyce Hughey
11/16/2011 Update or Other Action Site transferred from Don Fritz to Peter Campbell per Paul Horwath. Alyce Hughey
5/20/2014 Document, Report, or Work plan Review - other Reviewed the 2013 Groundwater Monitoring Report, dated March 19, 2014, prepared by Cook Inlet Environmental Inc. Groundwater monitoring was conducted in July, August and September of 2013, in accordance to the Agrium Kenai Nitrogen Operations Remedial Action Plan dated December 2006. The ammonia and urea plumes have decreased and leveled off, with the plums migrating down-gradient. The nitrate and nitrite trends within the plums show spikes in down-gradient wells, with all wells showing an increase in nitrate and nitrite in 2012, then a decrease in 2013. In October of 2008 the groundwater cleanup standard for arsenic was lowered from 50 ug/L to 10 ug/L. The arsenic concentrations have attenuated, and it is anticipated that the cleanup timeframe will be extended by at least three years for arsenic. High carbonate levels are present due to aerobic microbial processes in which urea is hydrolyzed to form ammonia, carbonate and elevated pH. These high carbonate levels discharge to the sea water that results in large slab-like rocks forming on the beach. Due to the carbonate levels between 2012 and 2013 no large slab-like rocks formed on the beach, therefore beach dredging was not conducted in 2013. The temperature within the upper confined aquifer and the semi-confined aquifer have reduced since the facility stopped operations in 2008. The rise in groundwater temperature was due to steam leaking from reclaim systems from Plants 2 and 5. It is expected that the groundwater temperature will continue to drop since the facility is no longer in operation. Alyce Hughey
8/31/2021 Document, Report, or Work plan Review - other Reviewed the 2020 Groundwater Monitoring Report. 1356 mg/l ammonia discharging on the beach. 1 mg/l can be toxic to marine life. Ammonia is stable to decreasing in the northern unconfined aquifer plume. The ammonia plume is migrating through the semi-confined aquifer. Urea attenuation s nearly complete in the semi-confined aquifer. Nitrate and nitrite concentrations are stable over the past six years which indicates that the ammonia degradation process may have slowed with the attenuation of high ammonia levels. The hydrographs for the unconfined aquifer indicate that the water elevation trend has increased 1.5 feet. 1 cubic yard of beach rock was removed. Peter Campbell
8/16/2022 Document, Report, or Work plan Review - other Review 2021 GWM Report. An unusual level of urea in beach well MW-38R has been identified. It is not know if this is an anomaly or a new source area. Peter Campbell

Contaminant Information

Name Level Description Media Comments

Control Type

Type Details

Requirements

Description Details

No associated sites were found.

Missing Location Data

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