A No Further Action determination is an approval by CDPHE that no further investigation or remediation is required for a particular site. The following pages present a brief description for each of the NFAs issued to LAC since 2002 and their location is shown on the NFA location map.
Between the early 1940’s and the late 1950’s, the Air Force had a complex of hospital buildings on fourteen acres of land located north of East 8th Avenue, west of Uinta Way, south of East 11th Avenue, and east of Spruce Court and Ulster Way. This area is now called the Northwest Neighborhood (NWN) of Lowry. The complex of buildings included the hospital and the hospital’s steam heating plant. The steam lines associated with the steam heating plant may have been wrapped in asbestos-containing insulation. The complex was demolished by the Air Force between 1963 and 1975 prior to any asbestos abatement regulations. When the buildings were demolished, not all of the building debris and piping were removed. Material containing asbestos has been found in the soil in the NWN and includes water pipes, some gas pipes, insulation material, and floor tile.
In 2003, during basement excavations for new construction, building debris with associated asbestos was discovered at depth. On April 2003, CDPHE issued Compliance Advisories for asbestos in soil in the NWN. The Compliance Advisories required sampling, emissions control, and response plans related to asbestos in soil.
In Privatization 2 (2005), LAC became responsible for sampling and remediation of 22 acres of Air Force owned property within the NWN, which included the former location of the base hospital heating plant. These areas consisted of Filing 28, 670 North, Building 667, and portions of Filing 16 and Building 670. LAC began sampling in April 2006 and completed sampling in August 2006. During the sampling, over 5,700 soil samples were taken. LAC commenced remediation of this property in May 2006 and completed remediation in August 2006.
On September 25, 2009, LAC submitted a Notice of Completion to close out all issues related to the 2003 Compliance Advisories for asbestos in soil on 22 acres in thte NWN within the scope of the privatization. The Notice and final NFA were approved by CDPHE on September 29th 2009.
Building 753 was used as a dental clinic by the Air Force and is currently used as a dental hygiene training facility by the CCCS. Prior to base closure in 1994, the Air Force reportedly prepared and used mercury-containing amalgams in this facility. No mercury has been used in the building since it was transferred from the Air Force to the CCCS in 1994. Previous investigations by the Air Force showed that mercury vapors were present in the building at concentrations below all applicable occupational exposure action levels but above the risk-based exposure level for unrestricted use.
Current redevelopment plans for Building 753 is demolition. Therefore, investigation efforts were focused on sampling and characterization of potential mercury releases in the context of building demolition. Inspection of the crawlspace was performed looking for evidence of release of mercury from the building into the underlying soil. Thirty discrete soil samples were collected from the crawlspace and were analyzed for total mercury. Bulk sample was also collected in order to characterize the building materials for disposal and was analyzed for mercury.
Mercury concentrations in all soil samples were below action level of 23 mg/kg and mercury was not detected in the building material TCLP analysis.
Based on the result of the sampling, LAC requested a No Further Action for Building 753 on October 20, 2009. CDPHE approved the request on October 23, 2009. In addition, LAC has completed all work related to the “Known Conditions that warrant further investigation and potential remedial activities” identified through the RFA. A list of completed tasks related to RCRA Facilities Assessment (RFA) Knowns and their NFA date are listed below.
Building 416 potential tank
Building 546, potential impact from dental clinic
Building 568, potential impact from dental clinic
Building 1496A potential tank
Building 1499, potential disposal of solvents
PAA-2 potential waste area
Building 777 potential beryllium
Potential PCB contamination
2/4/08 and 2/13/08
Building 753 potential mercury
On October 20, 2009, LAC also requested a NFA letter to close out all of the RFA Known Conditions. CDPHE approved the request on October 23, 2009.
Building 1002e Dayton Street Septic Tank
Building 1002E, near the intersection of 6th Avenue and Dayton Street, was formerly used as a general purpose warehouse and most recently used as a reclamation shop. According to RFA database, there were no reported releases of hazardous materials and there is no apparent surface contamination at the site. Sanitary sewer system drawings show that one septic tank and leach field served all of the buildings in this area including 10001, 1001, and 1002 and associated out buildings. The septic tank was removed in April 2005 and the contents of the septic tank and surrounding soil were evaluated by the Air Force at that time. Both the contents of the septic tank and the surrounding soils were determined to be non-hazardous. In addition, data from groundwater monitored from well CSZ-2, located within the Dayton Street Septic Tank leach field, do not indicate groundwater contamination.
On April 21, 2008, LAC submitted a NFA request to CDPHE for the Dayton Street Septic Tank. CDPHE approved the request on April 28, 2008.
Building 898 was a former dispensary and dental clinic, located in the northeastern corner of Lowry and shown on the map. Initial investigations of the building indicated that levels of mercury vapor measured in breathing zone air precluded unrestricted use. Additional sampling, was conducted, in 2002, to:
establish whether removal of primary sources (sinks and associated piping) would lower mercury vapor concentrations to levels permitting unrestricted use;
establish whether potential secondary sources are emitting mercury vapor; and
assess potential mercury contamination of soil and building materials in the crawlspace.
The results indicated that removal of the sinks and piping would likely lower mercury vapor concentrations in breathing zones to levels permitting unrestricted use. The results also indicated that mercury associated with the flooring materials could pose a risk. Elevated mercury vapor concentrations were not detected in the crawlspace.
Based on these data, the Air Force determined that Building 898 would be demolished. CDPHE approved the Air Force Study and demolition determination with the requirement that soil samples be collected during the demolition to assess whether there had been a release of mercury to the environment.
In April 2007, LAC submitted a letter work plan outlining the pre-demolition asbestos building inspection, the collection and analysis of debris waste generated during demolition, and soil sampling to be conducted following demolition. In addition, Building 898 was within a Lowry Historic District and consultation with the State Historic Preservation Office (SHPO) was required before demolition. The work plan also described the consultation with the SHPO and their approval for demolition in January 2007.
In August 2007, asbestos abatement was conducted and Building 898 was demolished. Soil samples for mercury were taken, analyzed, and the results indicate that they are below Lowry Soil Action Levels and TCLP standards. Following demolition, asbestos was identified in the soil and access to the site was restricted. CDPHE approved the plan for removal of the asbestos containing soil on January 22, 2008 and the project was completed in March 2008. The project report and No Further Action request was submitted to CDPHE on May 6, 2008. CDPHE approved the NFA request on June 18, 2008.
Yosemite Street Gate Plume
Groundwater contamination within the Yosemite Street Gate Plume consisted of a plume of BTEX, total volatile petroleum hydrocarbons (TVPH), and 1,2- DCA. The source of the plume was identified as former leaking underground storage tanks (USTs).
As soil vapor extraction (SVE)/air injection bioventing treatment system was installed at the site in 1995 to reduce concentrations of petroleum hydrocarbons in soil. The system was turned off in 1999 after a successful reduction of these compounds to concentrations below regulatory standards. After shutdown of the treatment system, groundwater monitoring was continued for an additional year. The data from these samples indicated that BTEX and TVPH were below regulatory standards and that these contaminants were not migrating offsite at concentrations exceeding these standards. However, concentrations of 1,2-DCA were above the regulatory standard of 0.38 ug/L. In March 2005, the regulatory standard for 1,2-DCA was increased to 5 ug/L. To ensure that concentrations of 1,2-DCA did not exceed 5 ug/L and that it was not migrating downgradient, two additional wells were installed in 2005 and 2006 and an additional round of groundwater sampling was conducted. The results indicated that 1,2-DCA did not exceed regulatory standards in any well and it was not migrating downgradient. The Yosemite Street Gate Site was closed in May 2007.
Fire Training Zone (FTZ) Soil
The FTZ was used by the U.S. Air Force for large-scale fire fighting training activities from 1946 to 1966. Fire training in the FTZ continued, on a much smaller scale, until 1980. During fire training exercises, contaminated waste material and fuel were placed on old aircraft or aircraft fuselages or fuel was spread on the ground and ignited.
From 1984 to 2002, several sampling programs were conducted at the FTZ to investigate potential contamination to soil and groundwater from fire training activities. In limited areas of the site, dioxins (polychlorinated dibenzo-p-dioxins [PCDDs]), furans (polychlorinated dibenzofurans [PCDFs]), and polynuclear aromatic hydrocarbons (PAHs) were detected in the soil. Three small groundwater plumes with TCE were also identified in this area.
In November 2003, the Air Force proposed a removal action for the contaminated soil and CDPHE approved the plan. Following privatization, LAC submitted a work plan for the implementation of soil removal and began work in March 2006. LAC excavated, transported, and disposed of the soil in the previously defined areas of PAH and dioxin/furan contamination. Soil samples were collected and analyzed to verify that cleanup standards had been met, after which the excavated areas were restored. The work was completed in March 2006 and CDPHE issued a No Further Action letter for the soil in May 2006. Groundwater remediation continues in this area.
Outdoor Firing Range (OFR) Soil
The OFR is located west of Dayton Street and south of East 6th Avenue. Operations at OFR began in the early 1940s and continued until at least the early 1960s. Investigations for potential contamination to the soil and groundwater were conducted between 1998 and 2003. Results of the investigations indicated lead and excess metal fragments from firing operations were located in bermed soil west and east of the concrete backstop walls. In addition, 20-mm target practice projectiles were also identified in one portion of the firing range berm. In 2004, the Air Force prepared an Action Memorandum for the OFR, which described a non-time critical removal action for soil containing lead, bullet fragments, and potential ordnance at the OFR. CDPHE approved the Action Memorandum and in 2006, after privatization, LAC prepared a work plan to implement the work. The objective of the work plan was to achieve a clean regulatory closure to residential standards for soil.
In February 2006, LAC began the work at OFR. This included:
Clearance for Munitions and Explosives of Concern (MEC)
Excavation of lead-impacted soil
Post-excavation sampling and analysis
Soil screening to remove any MEC, chemical stabilization, and disposal of the excavated soil
The work was completed in April 2006. A No Further Action recommendation, for soil, was approved by CDPHE in June 2006. Groundwater remediation continues in this area.
Buildings 546 and 568
Buildings 546 and 568 were constructed in 1941 as part of the hospital area complex in the northwestern portion of the former Lowry AFB. Building 546 was originally used as a dental clinic and was demolished in 1964. Building 568 was originally used for Nurses Quarters until 1955 and then was used as a dental clinic. Building 568 was demolished in the early 1970s. Mercury could have been a potential environmental contaminant, in the soil, and neither building had been investigated. During redevelopment and soil remediation for asbestos, in the area of Buildings 546 and 568, LAC and the LRA found no indication that foundation remnants or piping remained at the site of the former buildings and no indication of contamination were observed. Based on this information that was obtained, LAC submitted a NFA request for Buildings 546 and 568 in March, 2007. CDPHE approved the request in May 2007.
Building 777 was constructed in 1975 and is a former dental lab, used for grinding dental apparatus made from alloys containing beryllium. Because of the presence of beryllium, Building 777 was identified as a potential area of concern. Investigations at Building 777 identified the presence of beryllium on beams in the building but no detections of beryllium in air samples.
In July 2006, LAC submitted a sampling work plan for Building 777 to evaluate the levels of beryllium found at the site. Sampling was conducted in August 2007 and confirmed that there was beryllium in dust on the horizontal components of the ceiling beams that had been unaltered since the building’s use as a dental lab. The beryllium concentrations were above CDPHE action levels for unrestricted use. In August 2006, LAC performed remediation of five structural beams, cleaning the beams within proper critical containment work areas, collected confirmation wipe and air samples, and restored the building. In October 2006, LAC prepared a closure report recommending no further action for Building 777. CDPHE approved the NFA recommendation in November 2006.
Building 1496A was located adjacent to Building 1499 in the center of Lowry AFB and was associated with training activities. It was likely used for storage. In 1965, the building number was changed to 1493 and it was used for Administration and Technical Training Support. Adjacent to Building 1496A were multiple gasoline pump pits and a 5,000-gallon gasoline UST. No information was available regarding the removal of the UST during the RCRA Facilities Assessment records search. LAC conducted additional research, which linked previous investigations and closure documentation to this specific UST. Based on the information provided in the Air Force documents, LAC submitted a request for no further action to CDPHE in April 2007. It was approved in May 2007.
Powerhouse Plaza is immediately north of Powerhouse Place, between Spruce Street and Ulster. Historically, there had been tanks in the area of Powerhouse Plaza but adjacent tank investigations conducted by the Air Force did not indicate petroleum contamination in soil. In July 2006, during construction at Powerhouse Plaza, LAC’s on-site inspector identified petroleum-contaminated soil. Sampling and analysis confirmed that the primary contaminant was diesel fuel. LAC removed 318 cubic yards of soil and conducted post-excavation soil confirmation sampling to confirm that the residual concentrations are below the Lowry Soil Action Levels. LAC submitted a completion report and request for no further action for the Site to CDPHE in September 2006. CDPHE approved the closure in October 2006.
Building 667 was located in the Northwest Neighborhood and was identified as requiring sampling for asbestos in soil. In May 2006, LAC sampled the soil around Building 667, and submitted preliminary sampling results for this area that indicated that six grids tested positive for asbestos at <1%; four in the surface and two in the 0 to 2 foot below ground surface interval. Based on these data, LAC removed soil from these grids and those that tested positive during previous Air Force sampling. During the removal process, LAC:
Excavated, loaded, transported, and disposed of 168 cubic yards of asbestos contaminated soil
Remediated a total of 21 grids, of which 18 were remediated to 6 inches and 3 were remediated to 18 inches
Restored the site with 236 cubic yards of clean soil
During excavation and restoration of the site, no additional asbestos was identified.
LAC submitted a closure report for Building 667 in June 2006 requesting an approval for transfer of Building 667. CDPHE approved the request in September 2006.
The former Building 606 was located in the northwest quadrant of Lowry, approximately 300 feet south of 8th Avenue and 250 feet west of Uinta Way. Building 606 was a Base Exchange gas station that distributed gasoline for personal vehicle use. The Base Exchange operated four 10,000-gallon underground storage tanks (USTs) containing unleaded gasoline. The USTs were removed in 1996 and Building 606 was demolished in 1997. Environmental investigations in the area of Building 606 indicated petroleum in both soil and groundwater with the full extent of groundwater contamination being less than 0.2 acres. A corrective action plan (CAP) was submitted to the Division of Oil and Public Safety (OPS) in 2001.
In February 2002, remediation work began at Building 606. Approximately 3,576 cubic yards of petroleum-contaminated soils were removed from two excavations at the Site. The contaminated soils were transported off-site for disposal. Immediately following excavation activities, ORC® (a compound used to facilitate biological degradation of hydrocarbon impacts in soil and water) was mixed into the saturated soil and groundwater at the base of the excavations. The excavations were backfilled with pea gravel and clean stockpiled soil. The ground surface was then graded to the surrounding contours. To monitor the groundwater at the Site, seven groundwater monitoring wells were installed, sampled quarterly, and the samples were analyzed for BTEX and TPH-GRO. Groundwater monitoring data indicate that two of the seven wells had consistently had concentrations of benzene above the regulatory standard (5 ug/L). Groundwater from other wells showed low concentrations or no detections of benzene. The results indicated that some small petroleum-impacted source mass remained in place after the 2002 soil removal action. However, BTEX constituents were not moving downgradient.
In February 2006, LAC submitted a work plan for in situ remediation of the groundwater in the Building 606 area. As part of that plan, ORC® was injected at approximately 50 points within the groundwater plume boundary. In addition, five grab groundwater samples were taken in an east-west transect downgradient of the plume and samples from wells MW-01, MW-02, and MW-03 were also taken. Following the ORC® injection, groundwater from wells MW-01 and MW-03 was sampled monthly for 3 months, and then sampled quarterly.
Although the ORC® groundwater injections in March 2006 reduced the overall concentrations of benzene, detections of benzene in groundwater remained above the regulatory standards. Based on an evaluation of other potential remedial alternatives for petroleum constituents in groundwater, LAC selected and implemented a newer technology (BOS-200® Trap and Treat) that enhances natural biodegradation processes to breakdown BTEX and TPH. In May 2007, BOS-200® was injected at over 50 locations throughout the impacted area. Three weeks after the BOS-200® injections, groundwater was sampled from monitoring wells MW-01, MW-02, and MW-03 and analyzed for BTEX and TPH-GRO. All analytes were below regulatory standards or were not detected.
These wells were sampled two additional times, in September 2007 and December 2007. Results of the sampling indicated that the BOS-200® had effectively degraded the benzene and all analytes were below regulatory standards or were nondetect. In January 2008, LAC submitted a letter to CDPHE requesting no further action for Building 606. CDPHE approved the request on February 1, 2008.
In December 2005 , the Air Force completed the RCRA Facility Assessment (RFA) report. The RFA report identified sites requiring further investigation to determine whether there are impacts to soil from historical practices at each site and whether additional response actions were needed. Soil investigations at these sites included:
An investigation conducted at 15 buildings to further assess the disposition of polychlorinated biphenyl (PCB)-containing transformers that were reportedly stored in the buildings
Geophysical surveys at 2 buildings to ascertain whether underground storage tanks were still present
Subsurface investigation at 3 buildings (including the 2 buildings with geophysical surveys) in order to evaluate current soil conditions
In November 2007, LAC conducted detailed site inspections of 15 facilities to further assess the disposition of PCB-containing (or contaminated) transformers that were reported stored in the buildings during Lowry AFB's operational history. At one facility (Building 383), CDPHE conducted the inspection with LAC, to establish a consistent approach to the sites based on field observations. Observations were documented on a Transformer Inspection Form for each site, in field notes, and by taking digital photographs to document current conditions of the site. At 12 of these sites (Building 349, 353A , 354, 359,361, 383, 401, 811, 850, 903, 905, 999) no visual evidence of potential contamination from PCB-transformers, or, for one site, the former transformer location was extensively remodeled since the last inspection. Based on the site inspections, LAC recommended no further action for these 12 facilities. CDPHE approved the NFA recommendation on February 4, 2008.
For the three remaining sites with PCB-transformer concerns (Building 901, 959, 1499), the November 2007 inspections of these former transformer (or switch) locations inside the buildings indicated visual evidence of limited staining and potential contaminations but no evidence of significant leakage or spills. Wipe samples were collected from the most significantly stained areas that were observed. No PCBs were detected in the wipe samples collected from the stained areas on the concrete floors of the transformer vaults in Building 901 and 1499. In the wipe sample from Building 959, which was taken to characterize a small stained area in basement vault, Arochlor-1260 (a type of PCB) was detected below the regulatory standard. No other PCBs were detected. Visual inspection indicated that the concrete floor was in good condition, indicating limited potential for impacts to underlying soil.
Investigations were also conducted in November 2007 to address soil concerns at Building 1499 (potential solvent release), and Building 359 and former Building 416 (potential USTs). Five borings were sampled along the south edge of Building 1499 to assess potential impacts to shallow soil at this site from historical use of solvents. The analytical data and field observations indicated no adverse impacts to the shallow soil from historical solvent use. Only low concentrations of six VOCs were detected and all were below regulatory standards.
At Building 359, a geophysical survey was performed to assess the potential presence of an abandoned diesel UST, and soil borings were drilled and sampled at two anomalies, where the survey indicated potential buried metals. Results of the survey and sampling indicate that the buried metal represents a metal object (e.g., pipe) other than a UST. Samples from the soil borings indicate no detections of TPH gasoline and diesel range and only low detections of two VOCs were detected; both were well below regulatory standards.
At former Building 416, a geophysical survey was performed to assess the potential presence of USTs, including two 1,000-gallon gasoline UST and two 1,000 gallon diesel/heating oil USTs. Six soil borings were drilled and sampled adjacent to five geophysical anomalies. Results of the soil samples indicate no detections of TPH gasoline or diesel range and only concentrations of VOCs below regulatory standards. Although the geophysical survey indicated potential locations of buried metal, these anomalies could represent demolition debris, pipes, and a water line meter/valve, but not a UST. Characterization data, including analytical data and field observations indicated no adverse impacts to soil at former Building 416.
A request for no further action for these facilities was submitted to CDPHE in December 2007. CDPHE approved the NFA request on February 13, 2008.
Building 753 was also identified as requiring further investigation and will be addressed in the future.
Area PAA_2 was identified in the RFA as a site requiring additional investigation. An aerial photograph from 1952 was interpreted to show that PAA-2 was a possible debris pile at the end of a small roadway south of the eventual location of Building 1002. The debris pile was not present in aerial photographs from 1948 or 1955. Therefore, PAA-2 was interpreted to be a waste staging area sometime between 1948 and 1952. The size of PAA-2 is estimated to be approximately 0.13 acre.
Groundwater in the area of PAA-2 was characterized as part of investigations for OU5. In February 2006, a soil assessment in the PAA_2 area was conducted. The investigation included sampling from eight soil borings for visual and lithologic evaluation as well as PID readings. Samples from four borings were analyzed for VOC, SVOC, TVPH, TEPH and metals. The results of the visual evaluation indicate debris in only one sample; an asphalt covered pebble. No staining or high PID readings were observed in any sample.
The results of the site characterization activities indicated that there are no adverse environmental impacts from potential past activities at PAA-2. LAC submitted an NFA request on March 8, 2006 and CDPHE accepted their request in a letter dated March 14, 2006.