D. Frederick, B. Anderson, and M. Verdoorn - Battelle Energy Alliance
R. Wilhelmsen - CH2M-WG Idaho
Operations at facilities located on the Idaho National Laboratory (INL) Site release radioactive and nonradioactive constituents into the environment. These releases are in compliance with regulations and monitoring of these releases ensures protection of the public and environment. This chapter presents results from radiological and nonradiological analyses of various water samples collected at both onsite and offsite locations. Results from sampling conducted by the INL and Idaho Cleanup Project (ICP) contractors are presented here. Results are compared to the appropriate regulatory limit (e.g., liquid effluent discharge permit limits, U.S. Environmental Protection Agency [EPA] health-based maximum contaminant levels [MCL] for drinking water, and/or the U.S. Department of Energy [DOE] Derived Concentration Guide [DCG] for ingestion of water).
A general overview of the organizations responsible for monitoring the various types of water at the INL Site is presented in Section 5.1. Sections 5.2 and 5.3 describe liquid effluent and groundwater monitoring as required by the City of Idaho Falls and Idaho Wastewater Land Application Permits (WLAPs), and effluent monitoring that is done for surveillance activities only. The INL Site drinking water programs are discussed in Section 5.4. Section 5.5 describes surface runoff monitoring conducted at the onsite waste management facility.
The INL contractor and the ICP contractor monitor liquid effluent, groundwater, drinking water, and surface runoff at the INL Site to comply with applicable laws and regulations, DOE orders, and other requirements (e.g., WLAP requirements).
The INL Oversight Program collects split samples with INL Site contractors of liquid effluents, groundwater, drinking water, and storm water. Results of the Oversight Program’s monitoring are presented in annual reports prepared by that organization and are not reported here.
Table 5-1 presents the various water-related monitoring activities performed on and around the INL Site.
The INL contractor and the ICP contractor monitor nonradioactive and radioactive parameters in liquid waste effluent and groundwater. Wastewater is typically discharged to the ground surface and evaporation ponds. Discharges to the ground surface are through infiltration ponds, trenches, and a sprinkler irrigation system at the following areas:
Discharge of wastewater to the land surface is regulated under WLAP rules (Idaho Administrative Procedures Act [IDAPA] 58.01.17). A WLAP normally requires monitoring of nonradioactive parameters in the influent waste, effluent waste, and groundwater, as applicable. The liquid effluent and groundwater monitoring programs support WLAP requirements for INL Site facilities that generate liquid waste streams covered under WLAP rules. Table 5-2 lists the current WLAP status of each facility.
The permits generally require compliance with the Idaho groundwater quality primary constituent standards (PCSs) and secondary constituent standards (SCSs) in groundwater monitoring wells specified in the permit (IDAPA 58.01.11). The permits specify annual discharge volumes, application rates, and effluent quality limits. As required, annual reports (ICP 2007a, 2007b; INL 2007) were prepared and submitted to the Idaho Department of Environmental Quality (DEQ).
During 2006, the contractors conducted monitoring as required by the permits for the following facilities (see Table 5-2):
The RTC Cold Waste Pond has not been issued a permit; however, quarterly samples for total nitrogen and total suspended solids (TSS) are collected to show compliance with the regulatory effluent limits for rapid infiltration systems. The following subsections present results of wastewater and groundwater monitoring for individual facilities conducted for permit compliance purposes.
Additional parameters are also monitored in the effluent to comply with DOE Orders 5400.5 and 450.1 (DOE 1993, DOE 2003) environmental protection objectives. Section 5.3 discusses the results of liquid effluent surveillance monitoring.
Description – The City of Idaho Falls is authorized by the Clean Water Act, National Pollutant Discharge Elimination System to set pretreatment standards for nondomestic wastewater discharges to publicly owned treatment works. The INL contractor and U.S. Department of Energy-Idaho Operations Office (DOE-ID) facilities in Idaho Falls are required to comply with the applicable regulations in Chapter 1, Section 8 of the Municipal Code of the City of Idaho Falls.
Industrial Wastewater Acceptance Permits were issued for facilities that discharge process wastewater through the City of Idaho Falls sewer system. Twelve INL contractor facilities in Idaho Falls have associated Industrial Wastewater Acceptance Permits for discharges to the city sewer system. The Industrial Wastewater Acceptance Permits for these facilities contain special conditions and compliance schedules, prohibited discharge standards, reporting requirements, monitoring requirements, and effluent concentration limits for specific parameters; however, only the INL Research Center has specific effluent monitoring requirements.
Wastewater Monitoring Results – Table 5-3 summarizes the semiannual monitoring results conducted at the INL Research Center in April and October of 2006.
Description – The CFA Sewage Treatment Facility serves all major buildings at CFA. The treatment facility is southeast of CFA, approximately 671 m (2200 ft) downgradient of the nearest drinking water well.
A 1,500-L/min (400-gal/min) pump applies wastewater from a 0.2-ha (0.5-acre) lined, polishing pond to approximately 30 ha (74 acres) of desert rangeland through a computerized center pivot irrigation system. The permit limits wastewater application to 23 acre-inches/acre/year from April 1 through October 31.
WLAP Wastewater Monitoring Results – The permit requires influent and effluent monitoring, as well as soil sampling in the application area (see Chapter 7 for results pertaining to soils). Influent samples were collected monthly from the lift station at CFA (prior to Lagoon No. 1) during 2006. Effluent samples were collected from the pump pit (prior to the pivot irrigation system) starting in June 2006 and continuing through September 2006 (the period of irrigation operation for 2006). All samples collected were 24-hour flow proportional composites, except pH and coliform samples, which were collected as grab samples. Table 5-4 and Table 5-5 summarize the results. Additional samples for total Kjeldahl Nitrogen (TKN) and total phosphorus were collected in August to confirm the analytical results reported during June/July sampling events (Table 5-6).
Wastewater was intermittently applied via the center pivot irrigation system from June 21, 2006, to September 26, 2006. On the days it was operational, discharge to the pivot irrigation system averaged 606,370 liters per day (160,186 gallons per day).
A total of 6.43 million gallons (MG) of wastewater was applied to the land application area in 2006, which is equivalent to a loading rate of 3.22 acre-inch/acre/year. This is significantly less than the permit limit of 46 MG (23.0 acre-inch/acre/year). Hydraulic loading was highest in July and lowest in September. The nitrogen loading rate (1.89 lb/acre/yr) was significantly lower than the projected maximum loading rate of 32 lb/acre/yr. As a general rule, nitrogen loading should not exceed the amount necessary for crop utilization plus 50 percent. However, wastewater is applied to rangeland without nitrogen removal via crop harvest. To estimate nitrogen buildup in the soil under this condition, a nitrogen balance was prepared by Cascade Earth Science, Ltd., which estimated it would take 20 to 30 years to reach normal nitrogen agricultural levels in the soil (based on a loading rate of 32 lb/acre/year) (CES 1993). The low 2006 nitrogen loading rate had a negligible effect on nitrogen accumulation.
The 2006 annual total chemical oxygen demand (COD) loading rate at the CFA
Sewage Treatment Facility (32.72 lb/acre/year) was less than state guidelines of
50 lb/acre/day (which is equivalent to 18,250 lb/acre/year).
The annual total phosphorus loading rate (1.09 lb/acre/year) was below the
projected maximum loading rate of 4.5 lb/acre/year. The amount of phosphorus
applied was probably removed by sorption reactions in the soil and utilized by
vegetation, rather than lost to groundwater.
The INL Site contractor tracks operating parameters for the CFA lagoon for information only. For example, removal efficiencies (REs) were calculated to gauge treatment. The REs for biological oxygen demand (BOD) and TSS were above the design criterion of 80 percent, while COD was below the projected efficiency of 70 percent. The RE for total nitrogen was 71 percent. Since these estimates for information only, no action is required.
WLAP Groundwater Monitoring Results – The WLAP does not require groundwater monitoring at the CFA Sewage Treatment Plant.
Description – The INTEC New Percolation Ponds are a rapid infiltration system and comprised of two ponds excavated into the surficial alluvium and surrounded by bermed alluvial material. Each pond is approximately 305 ft × 305 ft at the top of the berm and is about 10 ft deep. Each pond is designed to accommodate a continuous wastewater discharge rate of approximately 3 MG per day.
The INTEC Sewage Treatment Plant (STP) is east of INTEC, outside the INTEC security fence. It treats and disposes of sanitary and other related waste at INTEC.
The STP depends on natural biological and physical processes (digestion, oxidation, photosynthesis, respiration, aeration, and evaporation) to treat the wastewater in four lagoons. After treatment in the lagoons, the effluent is gravity fed to lift station CPP-2714 where it is pumped to the service waste system. For the STP, automatic flow-proportional composite samplers are located at control stations CPP-769 (influent) and CPP-773 (wastewater effluent from the STP to the service waste system).
WLAP Wastewater Monitoring Results – Monthly samples were collected from:
All samples are collected as 24-hour flow proportional composites, except pH and total coliform, which are taken as grab samples as required by the permit.
The permit-required data are summarized in Table 5-7, Table 5-8, and Table 5-9. The permit for the INTEC New Percolation Ponds sets monthly concentration limits for the combined effluent (CPP-797) for TSS (100 mg/L) and total nitrogen (20 mg/L). During 2006, neither TSS nor total nitrogen exceeded the permit limit in the combined effluent, but the June 2006 result for TSS (99.9 mg/L) approached the permit limit (100 mg/L). The permit does not set limits for total nitrogen or TSS at CPP-769 and CPP 773. The 2006 Wastewater Land Application Report for the INTEC New Percolation Ponds (ICP 2007a) provides detailed wastewater monitoring results.
The permit specifies a hydraulic loading rate for the INTEC New Percolation Ponds of up to 3 MG per day or 1095 MG per year. During 2006, the maximum daily flow was 1.761 MG, and the total yearly flow to the INTEC New Percolation Ponds was 507.504 MG, both of which were below the permit limits.
WLAP Groundwater Monitoring Results –To measure potential impacts to groundwater from the INTEC New Percolation Ponds, the permit requires that groundwater samples be collected from six monitoring wells (Figure 5-1):
The permit requires that groundwater samples be collected semiannually during April and October and lists which parameters must be analyzed. Aquifer wells ICPP-MON-A-165 and ICPP-MON-A-166 and perched water wells ICPP-MON-V-200 and ICPP-MON-V-212 are the permit compliance points. Aquifer well ICPP-MON-A-167 and perched water well ICPP-MON-V-191 are listed in the permit as upgradient, noncompliance points. Contaminant concentrations in the compliance wells are limited by PCS and SCS specified in IDAPA 58.01.11, “Ground Water Quality Rule.” All permit-required samples are collected as unfiltered samples.
Table 5-10a, Table 5-10b shows the April and October 2006 depth to water table and water table elevations, determined before purging and sampling. The analytical results are reported as filtered and unfiltered for all parameters specified by the permit. Table 5-11a, Table 5-11b presents similar information for the perched water wells.
Aquifer well ICPP-MON-A-167 was dry during the April and October 2006 sampling events, and, therefore, could not be sampled. This well was dry for the first time in October 2005. Between October 2002, when WLAP sampling began, and October 2005, the depth of water in this well has ranged from approximately 150.9 m (495 ft) to just less than 152.4 m (500 ft). The pump is currently positioned near the bottom of this well and cannot be lowered further. Unless the water level rises above the pump intake, future WLAP compliance samples cannot be collected from this well. Similarly, water levels in wells ICPP-MON-A-165 and ICPP-MON-A-166 have also been decreasing (see Figure 5-2). In October 2006, an approximate 5.5-ft increase in water level in well ICPP-MON-A-166 was recorded.
During 2006, the Big Lost River flowed in the vicinity of the INTEC New Percolation Ponds from April 16 to July 4, 2006. Before 2006, the Big Lost River had been dry since May 2000, except for a 10-day period starting on May 31, 2005. Perched water well ICPP-MON-V-191 was sampled in April 2006; however, the well was dry during the October 2006 sampling event. Similarly, this well also was dry during the April and October 2005 sampling events. Water is in this well only when the Big Lost River is flowing; therefore, samples can be collected from this well only when the Big Lost River is flowing.
The majority of the permit-required monitoring parameters remained below their respective PCS or SCS during 2006 for all wells associated with the INTEC New Percolation Ponds. Exceedances were reported for three metals (aluminum, iron, and manganese) in unfiltered samples from three perched water wells and increased (but not exceeded) total dissolved solids (TDS) concentration in one aquifer well (see discussion below and in the 2006 Wastewater Land Application Report for the INTEC New Percolation Ponds [ICP 2007a]).
Aluminum, Iron, and Manganese Concentrations - Aluminum, iron, and manganese concentrations in unfiltered samples from permitted aquifer and perched water monitoring wells for the INTEC New Percolation Ponds have exceeded the associated groundwater quality standards in the past. Elevated concentrations were detected in preoperational unfiltered groundwater samples taken downgradient (aquifer well ICPP-MON-A-166) and upgradient (aquifer well ICPP-MON-A-167) of the INTEC New Percolation Ponds. For aquifer wells, the preoperational concentrations (see Table 5-12) in the upgradient aquifer well (ICPP-MON-A-167) are considered the natural background level (IDAPA 58.01.11.200.03) and are used for determining compliance with the permit and the “Ground Water Quality Rule.” If concentrations of aluminum, iron, or manganese in aquifer wells exceed an SCS, yet are below the preoperational upgradient concentrations, they are considered in compliance with the permit and the “Ground Water Quality Rule.” Preoperational samples could not be collected from the perched water wells because of insufficient water volumes. Therefore, the PCSs and SCSs from the “Ground Water Quality Rule” (IDAPA 58.01.11.200.01.a and b) are used for determining compliance for the perched water wells.
During 2006, the following parameters exceeded the associated groundwater quality standards:
As required by the permit, DEQ was notified of these exceedances (McNeel 2006).
Concentrations of aluminum in aquifer well ICPP-MON-A-166 and iron in aquifer well ICPP-MON-A-165 exceeded the associated SCS (see Table 5-10a, Table 5-10b); however, they were below the preoperational concentrations in upgradient aquifer well ICPP-MON-A-167 (see Table 5-12), and are considered in compliance with the permit and the “Ground Water Quality Rule.”
The April 2006 aluminum concentration in well ICPP-MON-V-191 exceeded the SCS (see Table 5-11a, Table 5-11b). However, the result was rejected due to poor laboratory serial dilution sample precision. The accuracy of this April 2006 data is questionable, and it is recommended that the data not be used.
Concentrations of aluminum and iron in the unfiltered samples from well ICPP-MON-V-200 were first measured above SCSs in April 2003. During 2006, concentrations of aluminum in the unfiltered samples from ICPP-MON-V-200 remained above the SCSs (see Table 5-11a, Table 5-11b). However, the April aluminum result was rejected due to poor laboratory serial dilution sample precision; therefore, the accuracy is questionable. The April iron result also exceeded the SCS, but was below the detection limit.
The concentration of iron in unfiltered samples from well ICPP-MON-V-212 was first measured above the SCS in October 2004, and remained above the SCS during 2006. Also in 2006, the April and October aluminum and April manganese concentrations exceeded the SCS in well ICPP-MON-V-212. This was the first exceedance of aluminum and manganese SCSs in well ICPP-MON-V-212. However, the April aluminum result was rejected due to poor laboratory serial dilution sample precision.
Until 2006, concentrations of aluminum and iron in all filtered samples from perched water wells ICPP-MON-V-191, ICPP-MON-V-200, ICPP-MON-V-212 were below the associated groundwater quality standards. This indicates that the elevated metals measured in unfiltered samples were not in solution in the perched water, but were associated with the sediment that dissolved during the analytical process (e.g., acidification).
Several studies have been performed and actions taken to address the high concentrations of aluminum, iron, and manganese in the permitted wells. The 2005 annual report (DOE 2006) summarizes the studies and actions. An investigation of exceedances of these and other constituents at the INL Site will be conducted during 2007. The results of the investigation will be reported in the 2007 annual report. Also, semiannual monitoring of the permitted wells will continue, and additional actions will be implemented as needed.
TDS Concentrations in Groundwater - During 2006, concentrations of TDS were below the SCS in the two downgradient aquifer wells and in all three perched water wells. As shown in Table 5-10a, Table 5-10b, the concentration of TDS in aquifer well ICPP-MON-A-165 increased considerably from April 2006 (266 mg/L) to October 2006 (354 mg/L). Since October 2002, TDS concentrations in this well have averaged 244 mg/L. In addition, the chloride concentrations in this well have steadily increased from a concentration of 8.9 mg/L in October 2002 to a concentration of 75.7 mg/L in October 2006, indicating that mobile contaminants in wastewater effluent from the CPP-606 Treated Water System is now impacting the aquifer in this area. In contrast, the concentrations of TDS in aquifer well ICPP-MON-A-166 have remained constant since 2002, with an average concentration of 187 mg/L.
The concentration of TDS in upgradient perched water well ICPP-MON-V-191 was 266 mg/L and below the SCS of 500 mg/L. The April 2006 and October 2006 TDS results for the two downgradient perched water wells, ICPP-MON-V-200 and ICPP-MON-V-212, were also below the SCS. However, the concentration of TDS in these two wells remained high, with a concentration of 472 mg/L in April and 426 mg/L in October for perched water well ICPP-MON-V-200, and a concentration of 430 mg/L in April and 471 mg/L in October for perched water well ICPP-MON-V-212. The wastewater effluent from the CPP-606 Treated Water System continues to impact the perched water in the vicinity of the New Percolation Ponds.
The concentrations of TDS, chloride, and sodium in the aquifer near aquifer well ICPP-MON-A-165 and in the perched water near the New Percolation Ponds are influenced by the wastewater discharges from the CPP-606 Treated Water System. To reduce concentrations of TDS, chloride, and sodium in the groundwater, a new water treatment system is being installed at INTEC and is expected to be operational by the end of 2007.
Actions To Address Groundwater Quality Standard Exceedances - Because of persistently high concentrations of aluminum, iron, and manganese in unfiltered samples taken from both aquifer and perched water wells, several investigative and corrective actions have been taken (ICP 2006a). These include analyzing sediment samples from permitted wells, well completion material (bentonite), and nearby interbeds; evaluating data from the Service Waste System effluent and previous well sampling events; evaluating metals data from additional INTEC area wells that are known to be outside the influence of the INTEC New Percolation Ponds; and performing additional well development. Several studies have indicated that the most likely source for the sediment in the permitted wells is washed-in interbed material and that the elevated concentrations of these metals in unfiltered samples taken from these wells can be attributed to the undissolved sediments in the samples. During analysis of unfiltered samples, metals concentrations in the liquid portion of the sample increase after the acidification process as aluminum and iron minerals are dissolved. This is supported by the fact that, before 2006, concentrations of these metals in all filtered samples taken from these wells have been below the associated groundwater quality standards, indicating that aluminum and iron are not in solution in the groundwater, at least in great quantities, but are associated with the undissolved sediment in the unfiltered samples.
The following will be implemented to address aluminum, iron, and manganese exceedances:
Description – The TAN/TSF Sewage Treatment Facility (TAN-623) was constructed and designed to treat raw wastewater by biologically digesting the majority of the organic waste and other major contaminants, then applying it to the land surface for infiltration and evaporation. The Sewage Treatment Facility consists of:
The TAN/TSF Disposal Pond was constructed in 1971 and consists of a primary disposal area and an overflow section, both of which are located within an unlined, fenced 14-ha (35-acre) area (see Figure 5-3). The Overflow Pond is rarely used; it is used only when the water is diverted to it for brief periods of cleanup and maintenance. The TAN/TSF Disposal Pond and Overflow Pond areas are approximately 0.4 ha (0.9 acres) and 0.13 ha (0.330 acres), respectively, for a combined area of approximately 0.5 ha (1.23 acres). In addition to receiving treated sewage wastewater, the TAN/TSF Disposal Pond also receives process wastewater, which enters the facility at the TAN-655 lift station.
The TSF sewage primarily consists of spent water containing waste from restrooms, sinks, and showers. The sanitary wastewater goes to the TAN-623 Sewage Treatment Facility, and then to the TAN-655 lift station, which pumps to the TAN/TSF Disposal Pond.
The process drain system collects wastewater from process drains and building sources originating from various TAN facilities. The process wastewater consists of liquid effluent, such as steam condensate; water softener and demineralizer discharges; fire water discharges; and cooling, heating, and air conditioning water. The process wastewater is transported directly to the TAN-655 lift station, where it is mixed with sanitary wastewater before being pumped to the TAN/TSF Disposal Pond.
WLAP Wastewater Monitoring Results – Total effluent to the TAN/TSF Disposal Pond for calendar year 2006 was approximately 41.03 million L (10.84 MG), which was under the permit limit of 15 MG per year. During 2006, an average of 29,690 gal per day was discharged to the TAN/TSF Disposal Pond.
The permit for the TAN/TSF Sewage Treatment Facility sets concentration
limits for TSS and total nitrogen (measured at the effluent to the TAN/TSF
Disposal Pond) and requires that the effluent be sampled and analyzed monthly
for specific parameters. During 2006, 24-hour composite samples (except pH,
fecal coliform, and total coliform, which were grab samples) were collected from
the TAN-655 lift station effluent monthly.
Table 5-13 shows the effluent monitoring results
for 2006. All monthly total nitrogen (total Kjeldahl nitrogen plus nitrate +
nitrite, as nitrogen) concentrations were below the permit limit of 20 mg/L. All
monthly TSS concentrations were below the permit limit of 100 mg/L. No permit
limits are established for other parameters. The 2006 Wastewater Land
Application Report for the TAN/TSF Sewage Treatment Facility (ICP 2007b)
provides detailed wastewater monitoring results.
In addition to the permit-required effluent monitoring, samples were collected at the Sewage Treatment Facility (TAN-623) (see Table 5-14). This additional monitoring was performed in anticipation of the reduced process wastewater flows to the TAN-655 lift station and to determine if there would be any nutrient loading and other impacts to the Disposal Pond. The results from TAN-623 are similar to the results from TAN-655 and were below permit limits.
WLAP Groundwater Monitoring Results – To measure potential TAN/TSF Disposal Pond impacts to groundwater, the permit requires that groundwater samples be collected from five monitoring wells (see Figure 5-3):
Sampling must be conducted semiannually and must include permit-specified parameters for analysis. As specified in Section F of WLAP-LA-000153-02, parameter concentrations in wells TAN-10A (except for iron), TAN-13A, and TANT-MON-A-002 are limited to the PCSs and SCSs in IDAPA 58.01.11, “Ground Water Quality Rule.” All permit required samples are collected as unfiltered samples.
During 2006, groundwater samples were collected in April and October. Table 5-15 shows water table elevations and depth to water table, determined before purging and sampling, and analytical results for all parameters specified by the permit. Well TSFAG-05 was dry during both April and October 2006. Therefore, no analytical results are presented for this well.
As Table 5-15 shows, groundwater parameters were below their respective PCSs and SCSs, except for the following exceedances:
Iron and filtered iron concentrations in well TAN-10A were above the SCS of 0.3 mg/L in April 2006 and October 2006 (see Table 5-15). However, Section F of WLAP LA-000153-02 exempts the iron concentrations in well TAN-10A from the limits set forth in IDAPA 58.01.11.200.01.b; therefore, these exceedances do not represent permit noncompliances.
The cadmium concentration in April for well TAN-10A was reported as undetected at the reporting limit of 0.010 mg/L. Although this result is above the PCS of 0.005 mg/L, a review of the raw data and supporting documentation indicate that cadmium was not present above the method detection limit of 0.004 mg/L. In addition, cadmium was not detected in the October 2006, October 2005, and April 2005 samples from this well, indicating groundwater concentrations were below the PCS. Cadmium was not a required groundwater parameter before the new permit was issued in January 2005.
The following subsections discuss exceedances of iron, manganese, TDS, and aluminum. The 2006 Wastewater Land Application Report for the TAN/TSF Sewage Treatment Facility (ICP 2007b) also discusses exceedances.
Iron Concentrations in Wells TAN-10A and TANT-MON-A-002- Unfiltered iron concentrations exceeded the SCS of 0.3 mg/L in well TANT-MON-A-002 in October 2006 (see Table 5-15). The concentration was 0.390 mg/L, which slightly exceeded the standard. A duplicate sample was collected at the same time, and that concentration was 0.509 mg/L.
Elevated iron concentrations historically have been measured in the TAN permitted monitoring wells; therefore, a corrosion evaluation (CORRPRO 2000) was performed. This evaluation confirmed that the riser pipes at several TAN wells were significantly corroded. The riser pipes were replaced with stainless steel riser pipes in all four TAN permitted monitoring wells during August 2001. After the riser pipes were replaced, iron concentrations decreased in wells TAN-13A, TANT-MON-A-001, and TANT-MON-A-002. Conversely, at well TAN-10A, both unfiltered and filtered iron concentrations increased immediately after the riser pipes were replaced. Unfiltered iron concentrations have since dropped, and filtered iron concentrations have continued to increase, and concentrations of both have consistently remained above the SCS (ICP 2006b).
Manganese and TDS Concentrations in Well TAN-10A - Concentrations of manganese and TDS in well TAN-10A exceeded their SCSs during 2006 (see Table 5-15):
As required by the permit, DEQ was notified of the exceedances.
For well TAN-10A, concentrations of both manganese and TDS have periodically been above their SCSs. The peak TDS concentration occurred shortly after riser pipe replacement, and the corroded well casing may still be contributing to the TDS concentrations in well TAN-10A. The 2004 annual report (ICP 2005a) stated that the TDS in the effluent could be impacting the concentrations in well TAN-10A. Figure 5-4 shows the historical TDS concentrations in the effluent and in well TAN-10A. While increases in well TAN-10A in early 2000 seem to follow earlier increases in the effluent, no pattern is evident from 2000 forward, with increases in well TAN-10A occurring prior to increases in the effluent. Similarly, no pattern is evident for the concentrations of manganese in the effluent when compared to concentrations in well TAN-10A.
To further evaluate manganese and TDS concentrations measured in the five permitted wells, 17 additional wells were sampled during 2006. The additional wells are within the trichloroethene plume, and five of the 17 wells are in the TSF-05 injection well hot spot. Exceedances of TDS and manganese were reported in all of the additional wells. The highest TDS concentration was 12,900 mg/L at well TAN-26 in April 2006. This concentration is approximately 20 times the highest concentration at well TAN-10A (620 mg/L). The highest manganese concentration was 6.94 mg/L at well TSF-05B in April 2006. This concentration is about 10 times greater than was measured in well TAN-10A in April (0.699 mg/L) and October (0.796 mg/L).
Aluminum Concentrations in Wells TANT-MON-A-002 and TAN-10A - The aluminum concentrations in two monitoring wells exceeded the SCS of 0.2 mg/L during 2006. The aluminum concentration in the sample collected from well TAN-10A on April 11, 2006, was 0.751 mg/L; the aluminum concentration in the sample collected from well TANT-MON-A-002 on October 9 2006, was 0.337 mg/L (duplicate was 0.394 mg/L) (see Table 5-15).
The historical data for wells TAN-10A and TANT-MON-A-002 show that aluminum was not detected in samples collected in April 2005, October 2005, or April 2006. Aluminum was not a required groundwater parameter for the permitted wells before the new permit was issued in January 2005. The historical data for other TAN area groundwater monitoring wells were also reviewed. From 1995 through 2006, there were only three other aluminum exceedances, which occurred in 2000 at wells TANT-MON-A-024 and TANT-MON-A-011.
Actions To Address Groundwater Quality Standard Exceedances - An investigation of exceedances of iron, manganese, TDS, and aluminum at the INL Site will be conducted during 2007. The results of the investigation will be reported in the 2007 annual report. Aluminum concentrations in wells TAN-10A and TANT-MON-A-002 will continue to be monitored.
The ICP contractor collected a surveillance sample from the Pit 9 production well on October 18, 2006, to evaluate the extent of carbon tetrachloride contamination at the RWMC. Of the 158 analyses, only 27 constituents were detected. The detected results, along with the applicable MCLs or secondary maximum contaminant levels (SMCLs), are shown in Table 5-16. Iron, manganese, and turbidity were the only three results that exceeded the MCLs or SMCLs.
As stated in Section 5.2, additional radiological and nonradiological parameters specified in the Idaho groundwater quality standards also are monitored. The following sections discuss results of this additional monitoring by individual facility. This additional monitoring is performed to comply with DOE Orders 450.1 and 5400.5 environmental protection objectives.
Both the influent and effluent to the CFA Sewage Treatment Facility (STF) are monitored according to the WLAP issued for the plant. Table 5-17 summarizes the additional monitoring conducted during 2006 at the CFA STF and shows those parameters with at least one detected result during the year. During 2006, most additional parameters were within historical concentration levels.
A WLAP is in effect for the INTEC New Percolation Ponds. Table 5-18 summarizes the additional monitoring conducted during 2006 at INTEC and shows the analytical results for parameters that were detected in at least one sample during the year. The 2006 INTEC New Percolation Ponds Radiological Monitoring Report (ICP 2007c) provides additional information.
During 2006, most additional parameters were within historical concentration levels.
During 2006, the Industrial Waste Pond, Industrial Waste Ditch, and Secondary Sanitary Lagoon were sampled monthly for iron, sodium, chloride, fluoride, sulfate, pH, conductivity, TSS, turbidity, biological oxygen demand, gross alpha, gross beta, gamma spectrometry, and tritium. Additionally, a sample for selected metals is collected once a year. The Industrial Waste Pond was dry for part of the year and was only sampled in June, July, October, and November. Table 5-19, Table 5-20 and Table 5-21 summarize the analytical results for parameters which were detected in at least one sample.
Cesium-134 was reported at an activity of 9.13 pCi/L in the sample collected from the Materials and Fuels Complex (MFC) Industrial Waste Ditch on August 16, 2006. Iron-55 and 95Zn were not detected in the first sample collected from the Industrial Waste Ditch on July 19, 2006; however, activities of 15.3 pCi/L and 7.83 pCi/L, respectively, were reported for the field duplicate. Iron-55 was also detected in the laboratory blank.
Two samples for low levels of uranium were collected from the Industrial Waste Ditch on July 19, 2006: a regular sample and a field duplicate. The activities of 233/234U in the sample and duplicate were 1.69 pCi/L and 1.85 pCi/L, respectively. The reported activities of 238U in the sample and duplicate were 0.705 pCi/L and 0.959 pCi/L, respectively.
A sample for low levels of uranium was collected from the Industrial Waste Pond on July 19, 2006. The 233/234U activity was 3.69 pCi/L, +U was reported at 0.147 pCi/L, and 238U was 1.82 pCi/L.
Tritium was detected in the samples collected from the Sanitary Sewage Lagoon in November and December.
The effluent to the TAN/TSF Disposal Pond receives a combination of process water and treated sewage waste. Additional monitoring for surveillance purposes is conducted monthly for metal parameters and quarterly for radiological parameters (with the exception of 89Sr, 129I, and tritium, which are monitored annually, and 90Sr, which was monitored monthly starting in March 2005). Table 5-22 summarizes the results of this additional monitoring for those parameters detected in at least one sample during the year. The 2006 TAN/TSF Radiological Monitoring Report (ICP 2007d) provides additional information.
During 2006, the concentrations of most additional parameters were within historical concentration levels.
The effluent to the Cold Waste Pond receives a combination of process water from various RTC facilities. Additional monitoring for surveillance purposes is conducted quarterly for metals and for radiological parameters. Table 5-23 summarizes the results of this additional monitoring for those parameters with at least one detected result.
During 2006, concentrations of sulfate and TDS were elevated in samples collected during reactor operation. These differences are caused by the normal raw water hardness, as well as corrosion inhibitors and sulfuric acid added to control the cooling water pH. Concentrations of sulfate and TDS exceeded the risk-based release levels for the RTC Cold Waste Pond of 280 mg/L and 560 mg/L, respectively, in March, May, and November.
The Radium-226 activity in the sample from the effluent to the RTC Cold Waste Pond collected on November 8, 2006, was 13.00 pCi/L. Radium-226 was not detected in the other samples.
In 1988, a centralized INL Site drinking water programs was established. Today, INL and ICP participates in the INL Site drinking water programs. During 2006, each contractor administered its own drinking water program. In 2006, RTC separated their multiple-use wells from the potable water by completing a new well dedicated to potable water usage only.
The INL Site Drinking Water Program was established to monitor drinking water and production wells, which are multiple use wells for industrial use, fire safety, and drinking water. According to the “Idaho Rules for Public Drinking Water Systems” (IDAPA 58.01.08), INL Site drinking water systems are classified as either nontransient or transient, noncommunity water systems. The transient, noncommunity water systems are at the Experimental Breeder Reactor No. 1 (EBR-I), Gun Range, Critical Infrastructure Test Range Complex (CITRC), and the Main Gate. The remaining water systems are classified as nontransient, noncommunity water systems, which have more stringent requirements than transient, noncommunity water systems.
The INL Site Drinking Water Program monitors drinking water to ensure it is safe for consumption and to demonstrate that it meets Federal and state regulations (i.e. that MCLs are not exceeded). The Federal Safe Drinking Water Act also establishes requirements for the INL Site drinking water programs.
Because groundwater supplies the drinking water at the INL Site, information on groundwater quality was used to help develop the INL Site drinking water programs. The U.S. Geological Survey (USGS) and the various contractors monitor and characterize groundwater quality at the INL Site. Three groundwater contaminants have impacted INL drinking water systems: tritium at CFA, carbon tetrachloride at the Radioactive Waste Management Complex (RWMC), and trichloroethylene at TAN/TSF.
As required by the state of Idaho, the INL Site Drinking Water Program uses EPA-approved (or equivalent) analytical methods to analyze drinking water in compliance with current editions of IDAPA 58.01.08 and Title 40 Code of Federal Regulations (CFR) Parts 141–143. State regulations also require the use of laboratories that either are certified by the state or by another state whose certification is recognized by Idaho. The Idaho DEQ oversees the certification program and maintains a listing of approved laboratories.
Currently, the INL Site Drinking Water Program monitors eleven onsite water systems. Drinking water parameters are regulated by the state of Idaho under authority of the Safe Drinking Water Act. Parameters with primary MCLs must be monitored at least once during every three-year compliance period. Parameters with secondary MCLs are monitored every three years based on a recommendation by the EPA. The three year compliance periods for the INL Site Drinking Water Program are 2005 to 2007, 2008 to 2010, and so on. Many parameters require more frequent sampling during an initial period to establish a baseline, and subsequent monitoring frequency is determined from the baseline.
Because of known contaminants, the INL Site Drinking Water Program monitors certain parameters more frequently than required. For example, the Program monitors for bacteriological analyses more frequently because of historical problems with bacteriological contamination. These past detections were probably caused by biofilm of older water lines and stagnant water. In routine compliance sampling for 2006, total coliform bacteria were not detected in any water systems.
During 2006, 533 routine samples and 76 quality control samples were collected and analyzed from CFA, CITRC, EBR-I, Gun Range (Live Fire Test Range), INTEC, Main Gate, MFC, RWMC, RTC, TAN/Contained Test Facility (CTF), and TAN/TSF. In addition to the routine sampling, the nonroutine samples are also collected. A nonroutine sample is one collected after a water main is repaired to determine if the water is acceptable for use before the main is put back into service. Thirty-one requests for nonroutine sampling were received during 2006.
Analytical results of interest (carbon tetrachloride, trichloroethylene, and tritium) and nitrate (required to be monitored annually) results for 2006 are presented in Table 5-24 and Table 5-25, respectively, and are discussed in the following subsections. EBR-I, CITRC, Gun Range, INTEC, Main Gate, MFC, RTC, and TAN/CTF were well below drinking water limits for all regulatory parameters; therefore, they are not discussed further in this report.
In 2006, the carbon tetrachloride concentration in the RWMC public water system remained below the EPA established MCL of 5 μg/L. The MCL applies only at the compliance point, which is the distribution system. The annual average for the compliance point of the distribution system was 4.13 μg/L. The annual average for the production well was 6.0 μg/L. Trichloroethylene concentrations in samples from the TAN drinking water Well #2 remained below the MCL during 2006.
The CFA water system serves approximately 700 people daily. Since the early 1950s, wastewater containing tritium was disposed to the Snake River Plain Aquifer (SRPA) at INTEC and at RTC through injection wells and infiltration ponds. This wastewater migrated south-southwest and is the suspected source of tritium contamination in the CFA water supply wells. This practice of disposing of wastewater through injection wells was discontinued in the mid-1980s.
In 2006, water samples were collected once from CFA #1 Well (at CFA-651), once from CFA #2 Well (at CFA-642), and quarterly from CFA-1603 (manifold) for compliance purposes. Since December 1991, the mean tritium concentration has been below the MCL at all three locations. In general, tritium concentrations in groundwater have been decreasing (see Figure 5-5) because of changes in disposal techniques, recharge conditions, and radioactive decay.
CFA Worker Dose – Because of the potential impacts to downgradient workers at CFA from radionuclides in the Snake River Plain Aquifer, the potential effective dose equivalent from radioactivity in water was calculated. CFA was selected because tritium concentrations found in these wells were the highest of any drinking water wells. The 2006 calculation was based on the mean tritium concentration for the CFA distribution system in 2006 (Table 5-24).
For the 2006 dose calculation, it was assumed that each worker’s total water intake came from the CFA drinking water distribution system. This assumption overestimates the dose because workers typically consume only about half their total intake during working hours and typically work only 240 days rather than 365 days per year. The estimated annual effective dose equivalent to a worker from consuming all their drinking water at CFA during 2006 was 0.32 mrem (3.2 μSv), below the EPA standard of 4 mrem/yr for public drinking water systems.
The RWMC production well is located in WMF-603 and supplies all of the drinking water for more than 500 people. The well was put into service in 1974. Water samples were collected at the wellhead and from the point of entry to the distribution system, which is the point of compliance, at WMF-604.
Since monitoring began at RWMC in 1988, there had been an upward trend in carbon tetrachloride concentrations until 1999. Since 1999, carbon tetrachloride concentrations have remained fairly constant. Table 5-26 summarizes the carbon tetrachloride concentrations at the RWMC drinking water well and distribution system for 2006. The mean concentration at the well for 2006 was 6.0 μg/L, and the maximum concentration was 6.5 μg/L. The mean concentration at the distribution system was 4.13 μg/L, and the maximum concentration was 4.5 μg/L.
A potential source of the carbon tetrachloride is the estimated 334,630 L (88,400 gal) of organic chemical waste (including carbon tetrachloride, trichloroethylene, tetrachloroethylene, toluene, benzene, 1,1,1-trichloroethane, and lubricating oil) that were disposed of at the RWMC before 1970. High vapor-phase concentrations (up to 2700 PPM vapor phase) of volatile organic compounds were measured in the zone above the water table. Groundwater models predict that volatile organic compound concentrations will continue to increase in the groundwater at the RWMC. To ensure the drinking water at RWMC remains safe and in compliance with the appropriate drinking water standards, the RWMC Potable Water VOC Reduction Project was initiated in 2006 to install a packed column air stripping system to remove carbon tetrachloride and other VOCs from the groundwater source.
Permanent chlorination was installed in 2003 because of a history of total coliform bacteria detection. Since permanent chlorination was installed, no coliform bacteria have been detected.
In 1987, trichloroethylene was detected at both TSF #1 and #2 Wells, which supply drinking water to approximately 200 employees at TSF. The inactive TSF injection well (TSF-05) is believed to be the principal source of trichloroethylene contamination at the TSF. Bottled water was provided until 1988 when a sparger system (air stripping process) was installed in the water storage tank to volatilize the trichloroethylene to levels below the MCL.
During the third quarter of 1997, TSF #1 Well was taken offline, and TSF #2 Well was put online as the main supply well because the trichloroethylene concentration of TSF #2 had fallen below the MCL of 5.0 μg/L. Therefore, by using TSF #2 Well, no treatment (sparger air stripping system) is implemented other than the chlorination system. TSF #1 Well is used as a backup to TSF #2 Well. If TSF #1 Well must be used, the sparger system must be reactivated to treat the water.
Figure 5-6 illustrates the concentrations of trichloroethylene in both TSF wells and the distribution system from 2000 through 2006. Past distribution system sample exceedances are attributed to preventive maintenance activities that interrupted the operation of the sparger system.
Table 5-27 summarizes the trichloroethylene concentrations at TSF #2 Well and the distribution system. TSF #2 Well is sampled for surveillance purposes only (not required by regulations), and the distribution system is the point of compliance (required by regulations). The mean concentration at TSF #2 Well and distribution system for 2006 are 2.48 μg/L and 1.73 μg/L, respectively, which are below the MCL.
In compliance with DOE Order 435.1, the ICP contractor collects surface water, as surface runoff, at the RWMC Subsurface Disposal Area from the location shown in Figure 5-7. The control location for the RMWC Subsurface Disposal Area is 1.5 km (0.93 mi) west from the Van Buren Boulevard intersection on U.S. Highway 20/26 and 10 m (33 ft) north on the T-12 Road.
Surface water is collected to determine if radionuclide concentrations exceed administrative control levels or if concentrations have increased significantly compared to historical data.
Radionuclides could be transported outside the RWMC boundaries via surface water runoff. Surface water runs off the SDA only during periods of rapid snowmelt or heavy precipitation. At these times, water may be pumped out of the SDA retention basin into a drainage canal, which directs the flow outside the RWMC. The canal also carries runoff from outside the RWMC that has been diverted around the SDA.
Surface water runoff samples were collected at the RWMC SDA during the first
and second quarters of 2006. Table 5-28 summarizes the results of human-made
radionuclides. All sample results were comparable to historical concentrations.
40 CFR 122.26, 2006, “Storm Water Discharges,” Code of Federal Regulations, Office of the Federal Register.
40 CFR 141, 2006, “National Primary Drinking Water Regulations,” Code of Federal Regulations, Office of the Federal Register.
40 CFR 142, 2006, “National Primary Drinking Water Regulations Implementation,” Code of Federal Regulations, Office of the Federal Register.
40 CFR 143, 2006, “National Secondary Drinking Water Regulations,” Code of Federal Regulations, Office of the Federal Register.
63 FR 189, 1998, “Final Modification of the National Pollutant Discharge Elimination System Storm Water Multi-Sector General Permit for Industrial Activities,” Federal Register, U.S. Environmental Protection Agency, September 30, p. 52430.
Cascade Earth Science (CES), 1993, Soil Suitability Investigation for Land Application of Waste Water, Central Facility Area, Idaho National Engineering Laboratory, July 8, 1993.
CORRPRO Companies, 2000, Observation Well Pipe Evaluation at Test Area North.
Gibs, J., Z. Szabo, T. Ivahnenko, and F. D. Wilde, 2000, “Change in Field Turbidity and Trace Element Concentration during Well Purging,” Ground Water, v. 38 (4), 577-588.
ICP, 2007a, 2006 Wastewater Land Application Site Performance Report for the Idaho Nuclear Technology and Engineering Center New Percolation Ponds (LA-000130-04), RPT-286, Idaho Cleanup Project.
ICP, 2007b, 2006 Wastewater Land Application Site Performance Report for the Test Area North/Technical Support Facility Sewage Treatment Facility (LA-000153-02), RPT-287, Idaho Cleanup Project.
ICP, 2007c, 2006 Radiological Monitoring Results Associated with the Idaho Nuclear Technology and Engineering Center New Percolation Ponds, RPT-288, Idaho Cleanup Project.
ICP, 2007d, 2006 Radiological Monitoring Results Associated with the Test Area North/Technical Support Facility Sewage Treatment Facility, RPT-289, Idaho Cleanup Project.
ICP, 2006a, 2005 Wastewater Land Application Site Performance Report for the Idaho Nuclear Technology and Engineering Center New Percolation Ponds (LA-000130-04), ICP/EXT-05-01106, Idaho Cleanup Project.
ICP, 2006b, 2005 Wastewater Land Application Site Performance Report for the Test Area North/Technical Support Facility Sewage Treatment Facility (LA-000153-02), ICP/EXT-05-01109, Idaho Cleanup Project.
ICP, 2005a, 2004 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory, ICP/EXT-04-00648, Idaho Cleanup Project.
IDAPA 16.02.13, “Certification of Water Quality Laboratories,” Idaho Administrative Procedures Act, State of Idaho Department of Health and Welfare, current revision.
IDAPA 58.01.08, “Idaho Regulations for Public Drinking Water Systems,” Idaho Administrative Procedures Act, State of Idaho Department of Health and Welfare, current revision.
IDAPA 58.01.11, “Ground Water Quality Rules,” Idaho Administrative Procedure Act, State of Idaho Department of Health and Welfare, current revision.
IDAPA 58.01.17, “Wastewater Land Application Permits,” Idaho Administrative Procedure Act, State of Idaho Department of Health and Welfare, current revision.
INEEL, 2004, 2003 Wastewater Land Application Site Performance Reports for the Idaho National Engineering and Environmental Laboratory (LA-000130-04), ICP/EXT-03-00009, Idaho National Engineering and Environmental Laboratory.
INL, 2007, 2006 Wastewater Land Application Site Performance Report for the Idaho National Laboratory Site’s Central Facilities Area Sewage Treatment Plant, INL/EXT-06-12044, Idaho National Laboratory.
Johnston, J., 2001, DEQ, to Stacey Madson, DOE-ID, “INEEL Test Reactor Area (TRA) Cold Waste Pond and Water Reactor Test Facility (WRRTF) Wastewater Disposal Ponds,” January 19, 2001.
Johnston, James, Idaho Department of Environmental Quality, to Frank M. Russo, Bechtel BWXT Idaho, LLC, and Richard B. Provencher, U.S. Department of Energy Idaho Operations Office, November 19, 2004, “1. Issuance of Wastewater Land Application Permit No. LA-000130-04 for the Combined Effluent to the INEEL INTEC New Percolation Ponds (Combined Municipal and Industrial Wastewater). 2. Termination of Wastewater Land Application Permit No. LA-000130-03 for the Service Waste System Effluent to the New Percolation Ponds (Industrial Wastewater only). 3. Termination of Wastewater Land Application Permit No. LA-000115-02 for the INTEC Sewage Treatment Plant (Municipal Wastewater),” CCN 53618.
Johnston, James, Idaho Department of Environmental Quality, to Richard B. Provencher, U.S. Department of Energy Idaho Operations Office, and D. Brent Rankin, Idaho Cleanup Project, October 25, 2005a, “Minor Modification “B”, Idaho National Laboratory, Idaho Nuclear Technology and Engineering Center (INTEC) New Percolation Ponds, Wastewater Land Application Permit LA-000130-04,” CCN 301371, PER-115.
Johnston, James, Idaho Department of Environmental Quality, to Jerry Etheridge, Bechtel BWXT Idaho, LLC, and John F. Kotek, U.S. Department of Energy Idaho Operations Office, January 26, 2005b, “Test Area North/Technical Support Facility Sewage Treatment Facility, Wastewater Land Application Permit No. LA-000153-02 (Municipal and Industrial Wastewater),” CCN 54792.
Johnston, James, Idaho Department of Environmental Quality, to Richard B. Provencher, U.S. Department of Energy Idaho Operations Office, and D. Brent Rankin, Idaho Cleanup Project, October 21, 2005c, “Minor Modification “B,” Idaho National Laboratory, Test Area North/Technical Support Facility, Sewage Treatment Facility, Wastewater Land Application Permit LA-000153-02,” CCN 301354, PER-37.
Mann, L. J., 1996, Quality-Assurance Plan and Field Methods for Quality-of-Water Activities, U.S. Geological Survey, Idaho National Engineering Laboratory, Idaho, U.S. Geological Survey Open-File Report 96-615, DOE/ID-22132.
Stoller, 2006, Idaho National Laboratory Site Environmental Report Calendar Year 2005, ISSN 1089 5469, STOLLER-ESER-97, DOE-ID-1208(05).
U.S. Department of Energy (DOE), 2003, “Environmental Protection Program,” DOE Order 450.1, January.
U.S. Department of Energy (DOE), 2001, “Radioactive Waste Management,” DOE Order 435.1.
U.S. Department of Energy (DOE), 1993, “Radiation Protection of the Public and the Environment,” DOE Order 5400.5, January.
U.S. Department of Energy-Idaho Operations Office (DOE-ID), 2002, Idaho National Engineering and Environmental Laboratory Storm Water Pollution Prevention Plan for Industrial Activities, DOE/ID-10431, Rev. 41, January.
U.S. Department of Energy-Idaho Operations Office (DOE-ID), 2001, Idaho National Engineering and Environmental Laboratory Storm Water Pollution Prevention Plan for Industrial Activities, DOE/ID-10431, Rev. 41, January.