Hypothetical Variance Application Based on Human-Caused Conditions Factor

1.  Facility Name and Address:

Norwest Forest Products

123 Industry Avenue

Beautiful, Oregon 97000

2.  Withdrawal Water Source and River Mile:

Cascadia River, RM 10.4

3.  Receiving Waterbody and River Mile:

Cascadia River, RM 10.2

4.  Water Quality Standards at Issue in the Application:

Norwest conducted a Reasonable Potential Analysis and determined that discharge from the facility’s non-contact cooling process would cause an exceedence of the human health criterion for the insecticide, dieldrin.

Dieldrin human health criterion (water + org): 0.0000053 mg/L

Note that the quantitation limit for dieldrin is 0.01 mg/L, so the default compliance limit is at 0.01 mg/L. The most sensitive beneficial use at issue for Cascadia River is public water supply. In addition, the Cascadia River is listed as an impaired waterbody on the 303(d) list for dieldrin and temperature, however, a TMDL has not been completed.

Norwest can meet all other water quality standards, including the aquatic life criterion for dieldrin.

5.  Reason for Variance Request (40 C.F.R. 131.10(g) factors):

40 CFR 131.10(g)(3) – Human caused conditions or sources of pollution prevent the attainment of the use and cannot be remedied or would cause more environmental damage to correct than to leave in place.

6.  Description of the Reasons Why Compliance with the Water Quality Standards Cannot be Achieved:

Norwest withdraws 25 L/s of water from the Cascadia River for use as non-contact cooling water. As a result of past anthropogenic activities, Cascadia River contains the legacy pollutant, dieldrin at the point of Norwest’s withdrawal.

Over the past few years, Norwest has worked in conjunction with DEQ to reduce the amount of water withdrawn from the Cascadia River to reduce water withdrawals and thermal loading to the River in order to benefit aquatic life. To accomplish this goal, Norwest runs the non-contact cooling water through multiple cooling passes, rather than directly discharging the cooling water after the first pass. While this process reduces the thermal loading to the waterbody, it concentrates the intake water 6 times above the ambient background concentration of dieldrin. This leads to an insignificant increase in the concentration of dieldrin present in Cascadia River after full mixing with Norwest’s discharge. However, Norwest does not contribute additional mass loadings of dieldrin to the discharge through its processes.

Norwest conducted an onsite source investigation to determine whether or not dieldrin was originating from their industrial processes. Results showed that dieldrin was only present in Cascadia River intake water (Attachment B). Based on DEQ and generally available material, Norwest believes that concentrations present in Cascadia River at the point of Norwest’s withdrawal represents legacy concentrations resulting from numerous past human activities in the watershed. Dieldrin is an insecticide that is extremely persistent and is now banned in the U.S. Dieldrin is likely contributed to the Cascadia River via non-point surface runoff from forest and agricultural lands. Since nonpoint source pollution is widespread and difficult to quantify, it would be very difficult for Norwest to initiate meaningful reductions of dieldrin throughout the watershed. As such, Norwest cannot remedy these sources of dieldrin.

As described further below, Norwest has also considered a number of alternative options for addressing the increased concentration of dieldrin in its effluent (when compared to the intake water from Cascadia River) posed by the facility’s passing of non-contact cooling water through multiple cycles. All of the options evaluated by Norwest are either not technically feasible to implement, or implementation would cause more environmental damage to correct than to leave the existing process in place.

7.  Water Quality Monitoring Data Summary (intake source, upstream receiving waterbody information, and determination of ambient background concentration for pollutants at issue):

Norwest withdraws water from River Mile 10.4 of the Cascadia River. The Cascadia watershed drains 878 square miles (561,920 acres), made up of two Oregon counties, encompassing all or part of a number of Oregon cities. Agriculture and forestry are the primary industries located within the watershed, with predominantly (>90%) private ownership of the lands within the watershed. Agricultural land use is most common in the lower elevation and western portions of the basin, while forestry land use occurs mainly in the eastern portion of the basin. Urban land use is concentrated around the four largest urban centers in the watershed making up less than five percent of the overall land use.

Norwest regularly monitors the water quality of the Cascadia River above its intake source. The data shows that dieldrin is regularly found in Norwest’s intake water. Based on the monthly monitoring data of the Cascadia River above Norwest’s intake for 2008 (Attachment A), the ambient mean concentration for dieldrin is 0.007. The harmonic mean flow of the Cascadia River is 50.4 cfs.

8.  Effluent Data Summary (effluent sampling and determination of downstream ambient concentration after mixing):

Based on 2008 monthly monitoring data (Attachment A), Norwest determined that the effluent produced through its recycled non-contact cooling water is 6 times the concentration found in the intake water. Therefore, the effluent concentration for dieldrin is 0.042 mg/L.

By calculating the harmonic mean flow of the Cascadia River, Norwest projected through calculation that after full mixing with the River it had increased dieldrin concentration to 0.00708 mg/L. This represents an ambient concentration increase in Cascadia River of 1.087%. Norwest also calculated effluent concentrations which would equate to a 3% and 5% increase in waterbody concentrations and that, in both cases, the in-stream concentration did not change significantly from the background ambient concentration of 0.007 mg/L (See chart below).

9.  Demonstration that advanced treatment technology is necessary to achieve compliance with the water quality standard for which the variance is sought.

There are no technology-based requirements which apply to Norwest’s non-contact cooling water process. In order to achieve attainment with the water quality standard for dieldrin, advanced treatment would be necessary.

10.  Treatment or Alternative Options Considered, and Justification Describing Why These Options are Either not Technically Feasible or Satisfy the Condition Described at 40 CFR 131.10(g)(3).

As noted previously, Norwest does not contribute additional mass loadings of dieldrin to its discharge through its own processes. Based on DEQ and generally available material, Norwest believes that the dieldrin present in Cascadia River at the point of Norwest’s withdrawal represents legacy concentrations resulting from numerous past human activities in the watershed.

Dieldrin is an insecticide that is extremely persistent and is now banned in the U.S. Dieldrin is likely contributed to the Cascadia River via non-point surface runoff from forest and agricultural lands. Since nonpoint source pollution is widespread and difficult to quantify, it would be very difficult for Norwest to initiate meaningful reductions of dieldrin throughout the watershed. As such, Norwest cannot remedy these sources of dieldrin.

Norwest has also considered a number of alternative options for addressing the increased concentration of dieldrin in its effluent posed by the facility’s passing of non-contact cooling water through multiple cycles. All of the options evaluated by Norwest are either not technically feasible to implement, or implementation would cause more environmental damage to correct than to leave the existing process in place.

Norwest first examined the possibility of using alternate source waters. However, no other suitable surface waterbodies are available in the nearby vicinity of the facility. Norwest also evaluated the possibility of utilizing groundwater. However, this option posed similar problems as the current water source, as the groundwater contained high concentrations of naturally occurring metals such as arsenic, which would create alternative water quality problems. Additionally, use of groundwater has the likely adverse effect of further reducing cold water flows into the Cascadia River by reducing discharge from natural seeps and springs hydrologically connected to the groundwater Norwest would be withdrawing from. The combination of additional arsenic loading and reduced cold water flows resulting from implementation of this alternative would cause more environmental damage than the insignificant increase in concentration posed by Norwest’s multiple pass through cooling process.

In order to address the water quality problems posed by Norwest’s current use of surface water from the Cascadia River, or the alternative use of groundwater, Norwest evaluated the use of advanced treatment methods capable of achieving the applicable compliance level of 0.010 mg/L. Theoretically, reverse osmosis (RO) can remove nearly all inorganic contaminants from water, as well as viruses and most organic contaminants, including some pesticides. The process removes contaminants from water using a semipermeable membrane that permits water, and not dissolved compounds, to pass through its pores. The contaminated water is subjected to high pressures that force pure water through the membrane, leaving pollutants behind in a brine solution. However, there are no full scale performance data available from wastewater treatment plants discharging to surface waters that indicate that pollutant removal is possible on a consistent basis. This may be due to the fact that few, if any, facilities have been required to reduce toxic pollutants to such low concentrations through the use of end-of-pipe treatment. The use of RO for treating wastewater is limited, and therefore performance data are scarce. Even if the necessary pollutant concentrations are achievable with RO, it is important to acknowledge the environmental damage caused by this potential technology: significant raw materials and high energy usage and the production of hazardous waste brine than would need to be disposed of. For a facility the size of Norwest, with a 571,000 gallons per day water usage, a reverse osmosis system may produce between 20,000 to 45,000 gallons per day of hazardous residuals that would need to be treated or land applied (per manufacturer’s equipment specifications and engineering projections). The intensive energy requirements and production of hazardous byproducts resulting from implementation of reverse osmosis would cause more environmental damage than the insignificant increase in concentration posed by Norwest’s multiple pass through cooling process.

Additional treatment technologies, including activate carbon and chemical coagulation may also be effective at treating the increase in dieldrin concentrations. However, both of these systems pose similar negative environmental consequences as the RO method, in that they both produce large amounts of hazardous substances. These concentrated hazardous materials pose a significant threat of site contamination, and leaching back to the environment from wherever they are finally located. Additionally, significant transportation costs and potential associated environmental damage resulting from any spills during transport would also result from moving the contaminated by-product to a permitted hazardous waste disposal facility.

Norwest next evaluated the possibility of land application of the wastewater, but this option is not feasible due to the terrain surrounding the Norwest facility. The area is largely developed and devoid of the necessary space required for land application.  

The final alternative considered was the replacement of Norwest’s multiple-pass cooling water process with a single-pass cooling water process. This alternative would require Norwest to withdraw significantly higher volumes of water from Cascadia River. However, this alternative may result in increased thermal loading to the system, as well as reductions to in-stream flow downstream of the intake point. Due to the presence of ESA-listed species, increased stream temperature and decreased steam flow associated with this alternative may be more environmental harming than an insignificant increase in concentration of dieldrin.

11.  Proposed Duration and Justification for the Requested Variance Term

Norwest believes that the variance term should be aligned with the NPDES permit cycle, rather than a period of lesser duration. Based upon the source investigation and assessment of the facility, it is believed that the source of dieldrin in Norwest’s effluent is from an upstream legacy source, which may take many years and active implementation of primarily non-point source controls in the watershed upstream of Norwest’s discharge to remedy.

12.  Proposed Interim Discharge Limitations Representing the Highest Level of Treatment Achieved during the Term of the Variance:

Norwest is not treating the intake water, however water is filtered for removal of solids and an anti-fouling chemical is added. The intake water is strictly used for cooling processes. Norwest will continue to operate the cooling system at the highest and best level possible.

13.  Potential for Increased Human Health/Aquatic Life Risk as a Result of the Variance:

Norwest believes that its discharge does not pose an unacceptable increase in human health risk above that already present in Cascadia River. Dieldrin is present in the upstream intake water, as well as in diffuse amounts throughout the basin. Norwest’s discharge contributes an estimated 1.1% increase in dieldrin concentration after full mixing, however we believe this represents an insignificant change to the concentration of dieldrin already present in Cascadia River.

There are no public drinking water intakes downstream of the facility to the confluence with the Willamette River, nor are there any other known drinking water uses of the Cascadia River downstream of Norwest’s discharge. In spite of this fact, Norwest believes that removal of the drinking water use would be inappropriate at this time, and that a variance is the more conservative avenue to address this issue.

There is the possibility for incidental ingestion of river water downstream of Norwest’s discharge from swimmers and kayakers, however, the exposure scenario protected by the human health criteria includes drinking 2 liters of water a day, which is much more than what is likely through incidental ingestion.