Canadian Cataloguing in Publication Data

Butcher, G. A. (George Alan), 1952-
Lower Columbia River, Hugh Keenleyside Dam to Birchbank,
water quality assessment and objectives

[Vol. 2] constitutes technical appendix.
ISBN 0-7726-1650-7

1.  Water quality - Columbia River 
2.  Water quality - British Columbia
I.  BC Environment. Water Quality Branch.
II. Title


TD227.B7B873 1992    363.73'942'097116    C92-092350-x

TABLE OF CONTENTS

• Canadian Cataloguing in Publication
• Figure 1. Lower Columbia River Map
• Tables
  • Table 1. Provisional Water Quality Objectives for the Lower Columbia River (Keenleyside Dam to Birchbank)
  • Table 2. Resin Acids Objectives
  • Table 3. Recommended Rereceiving Water Monitoring Keenleyside Dam to Birchbank
• Preface
• Introduction
• Hydrology
• Water Uses
• Waste Discharges
• Water Quality
• Water Quality Objectives
• Monitoring

PREFACE

Water quality objectives are prepared for specific bodies of fresh, estuarine and coastal marine surface waters of British Columbia as part of the Ministry of Environment, Lands and Parks' mandate to manage water quality. Objectives are prepared only for those waterbodies and water quality characteristics that may be affected by human activity now or in the near future.

Water quality objectives are based the BC approved and working criteria as well as national water quality guidelines. Water quality criteria and guidelines are safe limits of the physical, chemical, or biological characteristics of water, biota (plant and animal life) or sediment which protect water use. Objectives are established in British Columbia for waterbodies on a site-specific basis. They are derived from the criteria by considering local water quality, water uses, water movement, waste discharges, and socioeconomic factors.

Water quality objectives are set to protect the most sensitive designated water use at a specific location. A designated water use is one that is protected in a given location and is one of the following:

• raw drinking water, public water supply, and food processing
• aquatic life and wildlife
• agriculture (livestock watering and irrigation)
• recreation and aesthetics
• industrial water supplies.

Each objective for a location may be based on the protection of a different water use, depending on the uses that are most sensitive to the physical, chemical or biological characteristics affecting that waterbody.

Water quality objectives routinely provide policy direction for resource managers for the protection of water uses in specific waterbodies. Objectives guide the evaluation of water quality, the issuing of permits, licences and orders, and the management of fisheries and the province's land base. They also provide a reference against which the state of water quality in a particular waterbody can be checked, and help to determine whether basin-wide water quality studies should be initiated.

Water quality objectives are also a standard for assessing the Ministry's performance in protecting water uses. While water quality objectives have no legal standing and are not directly enforced, these objectives become legally enforceable when included as a requirement of a permit, licence, order, or regulation, such as the Forest Practices Code Act, Water Act regulations or Waste Management Act regulations.

Water quality objectives are established to protect all uses which may take place in a waterbody. Monitoring (sometimes called sampling) is undertaken to determine if all the designated water uses are being protected. The monitoring usually takes place at a critical time when a water quality specialist has determined that the water quality objectives may not be met. It is assumed that if all designated water uses are protected at the critical time, then they also will be protected at other times when the threat is less.

The monitoring usually takes place during a five week period, which allows the specialists to measure the worst, as well as the average condition in the water.

For some waterbodies, the monitoring period and frequency may vary, depending upon the nature of the problem, severity of threats to designated water uses, and the way the objectives are expressed (i.e., mean value, maximum value).

INTRODUCTION

The status of existing and future water quality is examined with respect to the existing and future water uses. Provisional water quality objectives are set to protect designated water uses. A monitoring program to check the attainment of these objectives is recommended. The goal of this report is to guide the water quality management of this reach of the Columbia River. A detailed technical appendix was prepared and forms the basis for the conclusions presented in this summary.

HYDROLOGY

The mean annual flow of the Columbia River at the Keenleyside Dam increases from 1110 m³/s at the Keenleyside dam to 2020 m³/s at Birchbank. The Kootenay River is the largest tributary within this reach contributing to 42% of the mean annual flow at Birchbank. The Kootenay River thus provides significant dilution for anthropogenic discharges within this reach.

WATER USE

A total of 22 fish species are known to inhabit the Columbia River between the Keenleyside Dam and the US border. Of these, there are six important sport fish species: rainbow trout, yellow walleye, mountain whitefish, kokanee, Dolly Varden char, and burdot Their presence provides for a popular sport fishery which is the dominant water-based recreational activity in this reach. Other recreational attributes of the river are boating, swimming, aesthetics (tourism, viewing). Water quality has been identified as the principle factor detracting from the enjoyment of the river recreation in this reach.

WASTE WATER DISCHARGES

Non-Point Sources

Diffuse-source contamination from land activities does not appear to have any significant effect on river water quality. Agriculture is largely part-time and limited to small-scale livestock production and irrigated hay crops. There are some unpermitted domestic effluent discharges within the potential for local fecal contamination, but not discerned by available river water quality monitoring data. There are two landfills operated by the sawmill and pulp mill located approximately 150 m from the river's edge; however, leachate is routed to an exfiltration pond and effects in the river have not been measured. Water-based log storage and handling at the sawmill and pulp mill have altered the benthos with sunken logs, branches, and bark debris, and has the potential (though undocumented) to degrade the quality of the overlying water column.

Celgar Pulp Mill

The Celgar pulp mill is the oldest interior kraft pulp mill and, since start-up in 1961, it has discharged u treated effluent to the Columbia River via a submerged diffuser located 3.3 km downstream from the Keenleyside Dam. Although some progress in effluent improvement has been made in recent years, by present industry standards the pulp mill is functionally obsolescent. Beginning in 1991, Celgar is rebuilding and expanding the mill, increasing production from 560 to 1200 ADt/d. Approval for the expansion was given after review by a panel convened jointly by the Federal and Provincial Governments. Details of the mill process changes are provided in the Technical Appendix.

Important future changes relative to receiving water quality include: installation of secondary treatment; a reduction in mean effluent flow from 116 000 m³/d to 93 000 m³/d (summer) and 76 900 m³/d (winter); a 40% reduction in chlorine usage; and reduction in chlorinated dioxins and furans to levels below current detection limits. Reduction in the effluent levels of BOD, suspended solids, colour, and toxic organics (Absorbable Organic Halogens (AOX), resin acids, phenolics) are also expected after 1994 with the completion of mill modernization. Effluent phosphorus levels are expected to remain high (102 kg/d compared to present loading of 112 kg/d), while nitrogen levels are expected to increase from the present level of 350 kg/d to 511 kg/d.

The effluent from the Celgar pulp mill in its pre-modernized condition has consistently exceeded permit target levels for BOD, suspended solids, pH, and toxicity. Rainbow trout bioassay data indicate that the 96-h LC₅₀ of the effluent ranged from 2.6 to 30% and averaged 13%. Extrapolation from the bioassay data indicates that receiving water concentrations at low flow were 7 to 70 times higher than the safe levels recommended for persistent and cumulative toxicants, after complete mixing. With the exception of levopimaric acid and the chlorinated resin acids, all of the resin acids have been measured at levels exceeding their reported 96-h LC₅₀ values, indicating their presence in the effluent at acutely lethal levels. Total organochlorines, as measured by AOX, averaged 4.8 kg/ADt in the pre-modernized mill, which is close to twice the Ministry mandated level of 2.5 kg/ADt (for 1991). The organochlorines identified from the effluent included 2,3,7,8-TCDF, H₆CDD, all five chlorophenol congeners (mono- to penta-), the chloroguaiacols, and chlorocatechols. With mill modernization proceeding, Celgar is expected to meet the 1.5 kg/ADt objective by July 1, 1994.

The City of Castlegar

The City of Castlegar has two separate secondary sewage treatment systems: one on the north bank of the river authorized to discharge 45% of the City's effluent and one on the east side of the river authorized to discharge the remainder. All available for the total effluent in the Columbia River is in excess of 5000:1.

WATER QUALITY ASSESSMENT

The colour of the Columbia River between the mill and the Kootenay River was degraded by the effluent to dark brown and could reach levels which impaired the water for downstream recreational use and for drinking water. Surface foaming, taste, and odour problems due to the pulp mill effluent are also recurring aesthetic problems with the mill in its present state. Mill modernization is projected to reduce (although not eliminate) the discolouration and eliminate the foaming, taste, and odour problems.

Acute toxicity was not a problem in the Columbia River downstream from Celgar's discharge outside the initial dilution zone; however, sublethal stress on aquatic organisms was expected to occur between Celgar and the Kootenay River confluence under present pre-modernized conditions. With mill modernization and secondary treatment, there should be few sublethal effects beyond the initial dilution zone. Receiving water resin acid levels were within the BC working criteria for the protection of aquatic life and by themselves were not responsible for sublethality outside the initial dilution zone. Organochlorines (as measured by AOX) have contaminated the water column of the river downstream from the mill to at least the US border. All receiving water chlorophenol measurements, however, have been less than the interim BC criteria for the protection of aquatic life. The only dioxin/furan congener detected in the receiving waters has been H₇CDD at 0.12 pg TCDD TEQ/L, which is considerably lower than the interim guideline for dioxins in drinking water (15 pg/L). The sediments downstream from Celgar have also been found to be contaminated with organocholorines, including EOX, dioxins (H₆CDD, H₇CDD, OCDD), furans (TCDF, PCDF), and chlorinated phenolics (guaiacols, catechols, anisoles, and veratroles).

Fibre discharge from the mill has resulted in fibre-matting on the bottom of the Columbia River for up to 2 km downstream from Celgar. The fibre mat is comprised of decomposed pulp fibres, fine sediments, and a slime covering or biofilm. Chemical analysis of this material indicates that organocholorines are present, but not at levels which could classify the material as "special waste" under the proposed MOE Special Waste Regulations.

High levels of dissolved gases were present downstream from the Keenelyside Dam as far as the Roosevelt Reservoir. Approximately 80% of dissolved gas measurements have exceeded 110%, which is the approximate threshold for acute effects. It is not presently known to what extend gas supersaturation affects the health of aquatic life in the Columbia River. Severe gas bubble disease observations have not been made to date, nor have there been significant fish kills reported. Installation of turbines in the Keenleyside Dam, as proposed by BC Hydro, would ameliorate gas supersaturation for most of the year when the sluiceway is not used.

Celgar's effluent has had minimal effect on the suspended solids, pH, or dissolved oxygen of the receiving waters. Water column pH has continued to remain in the pH 6.5 - 8.5 range, thereby meeting the approved BC criteria for pH. There is also no evidence from monitoring data that effluent induced suspended solids have exceeded 10 mg/L over background, BC's approved criteria for the protection of aquatic life. All surface dissolved oxygen data for this reach have been high, exceeding 10 mg/L. The supersaturated conditions created by the Keenleyside Dam allow for ready assimilation of the high BOD loading from the pulp mill. Even with a future scenario of reduced dissolved gas supersaturation (due to turbine installation at Keenleyside Dam), dissolved oxygen levels are not projected to fall below a minimum of 9.5 mg/L (largely because of mill modernization and BOD reductions).

The Celgar mill accounted for approximately 90% of the total phosphorus and 92% of the total nitrogen entering this reach of the Columbia River; however, these loadings have not contributed to eutrophication or excess algal growth. Predicted receiving water nutrient concentrations for post-expansions have been calculated and indicate no change over present total phosphorus increases, but a three-fold increase in the Kjeldahl nitrogen concentration. This indicates that mill expansion could further increase the phorphorus limitation on downstream algal growth.

Benthic Macroinvertebrates

The available information shows that some toxicity effects have occurred among the more sensitive benthic macroinvertebrate populations of the Columbia River within this reach. Sensitive organisms are no longer a significant component of the benthic community. There has been an accommodation of community structure with invertebrates classed as tolerant and facultative (considered less desirable from a fish-food perspective) dominating from Celgar to the Kootenay River.

Analysis of freshwater mussel tissue has indicated the presence of chlorophenol, chloroguaiacol, and dioxin/furan contamination in animals sampled downstream from Celgar. Low levels of TCDD and TCDF were present in mussels taken upstream from Celgar. The implications of these mussle tissue organochlorine levels for the health of the mussle community is presently unknown. These levels, however, may be sufficiency high to be unsafe for wildlife and human consumers.

Fish Tissue Dioxin and Furan Residues

The furan 2,3,7,8-TCDF has been the predominant congener contaminating the fish of the Columbia River, with the highest levels found in whitefish and sturgeon. In a North American context, the TCDF levels downstream from Celgar were high and would rank among the most contaminated samples measured to date. Dioxins also contaminate the lake whitefish (2,4,7,8-TCDD) and rainbow trout (OCDD, H₆CDD, H₇CDD) in this reach. All of the fish species tested downstream from Celgar had tissue TCDD TEQ levels exceeding the threshold for EROD (an hepatic mixed function oxidase enzyme) induction, an early warning stress threshold. TCDD concentrations in whitefish eggs from Roosevelt Reservoir had also exceeded the TCDD concentration in lake trout eggs reported to cause 50% mortality (LD 50) in swim-up fry. This suggests the possibility of reproduction impairment in the fish community downstream from Celgar. The majority of samples also exceeded a reported tissue criterion for the protection of wildlife feeding primarily on fish.

WATER QUALITY OBJECTIVES

These objectives apply to all parts of this reach of the Columbia River, except for the initial dilution zones of effluents. This is the initial part of the mixing zone where the Province accepts some degree of adverse biological effect, i.e., sublethal stress, but not conditions that are acutely toxic or that would cause harmful bioaccumulation, or adverse sludge deposits. For this reach of the Columbia River these excluded dilution zones are defined arbitrarily as extending up to 100 m downstream from the discharge point from the surface to the bottom and no more than 50% across the width of the river for the pulp mill discharge and no more than 25% for all other discharges. Initial dilution zones are not to impinge on bathing beaches or fish spawning habitat.

Water quality objectives have no legal standing and would not be directly enforced. The objectives can be considered as policy guidelines for resource mangers to protect water uses in the specified water bodies. They will guide the evaluation of water quality, the issuing of permits, licenses, and orders, and the management of the fisheries and of the Province's land base. They will also provide a reference against which the state of water quality in a particular water body can be checked, and serve to make decisions on whether to initiate basin-wide water quality studies.

Depending on the circumstances, water quality objectives may already be met in a water body, or may describe water quality conditions which can be met in the future. To limit the scope of the work, objectives are only being prepared for waterbodies and for water quality characteristics which may be affected by man's activity, now and in the foreseeable future.

The provisional objectives for dissolved oxygen, pH, temperature, resin acids, and suspended solids and turbidity are presently being met all of the time and can also be met in the future. The provisional objectives for colour, substrate sedimentation, and dissolved gases are not being met at present and are not projected to be met in the near future right at the edge of the initial dilution zone for the Celgar mill (although the dissolved gases objective can be met with future changes to the Keenelyside Dam). Those characteristics which are exceeding the recommended objectives at present, but which could meeting them in the near future with pulp mill modernization and secondary treatment, include toxicity and chlorinated resin acids. The objectives for dioxins and furans in fish tissue and sediment, presently exceeding the objectives, may take a longer time for attainment as levels in the sediments and food-chain are dissipated. At this time there are insufficient data to determine whether the objectives for microbiological indicators, periphyton standing crop, chlorophenols, or chlorinated dioxins and furans (in water) are being met at or could be met in the future.

WATER QUALITY MONITORING

TABLES