Canadian Cataloguing in Publication Data

Nordin, Richard Nels, 1947-
Quatse Lake, water quality assessment and objectives

Consists of two parts: An overview and a report, of which the overview is also available as a separate document.

Includes bibliographical references: p.
ISBN 0-7726-3414-9

1.  Water quality - British Columbia - Quatse Lake.
I. Phippen, B. W.  II.  BC Environment. Water Quality Branch.
III. Title


TD227.B7N675 1997    363.739'42'097112    C97-960319-6

TABLE OF CONTENTS

• Canadian Cataloguing in Publication
• Summary
• Figure 1. Quatse Lake Location Map
• Water Quality Objectives and Monitoring Tables
  • Table 1. Water Quality Objectives for Quatse Lake
  • Table 2. Recommended Water Quality Monitoring for Quatse Lake
• Preface
• Introduction
• Hydrology
• Water Uses
• Waste Discharges
• Water Quality Assessment
• Water Quality Objectives
• Monitoring Recommendations
• Glossary

This document is one in a series that presents ambient water quality objectives for British Columbia. It has two parts: an overview-which is available as a separate document-and the report. The overview provides general information about water quality in Quatse Lake. It is intended for both technical readers and for readers who may not be familiar with the process of setting water quality objectives. It includes tables listing water quality objectives and required monitoring. The main report presents the details of the water quality assessment for the lake and forms the basis of the recommendations and objectives presented in the overview.

Quatse Lake has low fisheries productivity, resulting in limited appeal for this type of recreational activity. The lake and its outlet stream (Quatse River) are used as drinking water supplies for the Mount Waddington Regional District. The water is currently treated with large amounts of chlorine to disinfect the water and reduce the concentration of colour present.

Most water contamination seems to come from past forestry activities, with about 25% of the watershed having been logged. However, it is difficult to completely isolate impacts which may have arisen due to logging activities.

Water quality objectives are recommended to protect aquatic life, wildlife and drinking water supplies with disinfection only. The objectives have been prepared for Environmental Managers for use in determining compliance with the Forest Practices Code of BC.

Purpose of Water Quality Objectives

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 socio-economic 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).

Quatse Lake is located on the north-eastern end of Vancouver Island, approximately three kilometers north from Coal harbour (see Figure 1.), and is the primary source of drinking water for the town. Currently, the water is treated with large amounts of chlorine prior to drinking to disinfect the water and reduce the concentration of colour. Recent logging activity in the lake watershed has raised concerns that the water quality might be affected.

The purpose of this report was to provide Environment Managers water quality objectives for Quatse Lake for use in determining compliance with the Forest Practices Code of BC.

HYDROLOGY

Flows into Quatse Lake come from Bluebell Creek to the west, with estimated flows from 0.037 to 0.124 m³/s in the April to September period and to as high as 1.03 m³/s in January. Return periods could not be calculated since these flows were estimates based upon precipitation measurements.

WATER USES

Aquatic biological productivity in the lake is low, resulting in a small amount of recreational fishing.

WASTE DISCHARGES

There are also several mining claims in the watershed; however, none are currently mined actively.

WATER QUALITY ASSESSMENT

Metal concentrations in Quatse Lake were usually below the BC approved or working water quality criteria except for occasional higher concentrations of iron or aluminum. This is typical in coastal lakes and no objectives were set.

Phosphorus concentrations were low enough to not cause excessive algal growth but watershed disturbance may cause an increase in phosphorus. For this reason, an objective is set in order to monitor this aspect of water quality.

Dissolved oxygen concentrations were usually satisfactory, but late summer concentrations in the deep water were low enough to be of some concern. Since these levels should not decrease (potentially by future anthropogenic activities, including logging) further, an objective is set to protect aquatic life.

The natural colour of the lake is very high, typically in the range of 50 to 100 true colour units, as a consequence of input of organic acids from watershed vegetation. The mean colour value (82 true colour units) exceeds the criteria for drinking water (75 units). A long-term objective of 75 units is set for raw drinking water recognizing that some management efforts may be needed to achieve this.

Turbidity values are typically low (less than 1 NTU) but there are times during high runoff and summer algal blooms when this may be exceeded. The objective is set for 1 NTU.

Fecal coliform concentrations are generally very low, below criteria and the objective set (10/cL). Fecal coliforms are very important indicators that need to be included in an objectives monitoring program.

Trihalomethanes (THM's) were found to be in relatively high concentrations for samples taken of treated water (after chlorination) at the tap. The high THM's are due to high amounts of natural organic material in the water (which are measured as total organic carbon and colour). Monitoring of THM's at the tap should be undertaken by the appropriate health authority as they may represent a significant human health risk.

The remainder of the general ion chemistry values are low and of little concern.

WATER QUALITY OBJECTIVES

Water quality objectives have no legal standing and would not be directly enforced. The objectives can be considered as policy guidelines for resource managers to protect water uses in the specified waterbodies. They will guide the evaluation of water quality, the issuing of permits, licences 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 qual;ity characteristics which may be affected by human activity now and in the foreseeable future.

Designated water uses for all three waterbodies (Quatse lake, Quatse River and Bluebell Creek) are for the protection of aquatic life, wildlife and drinking water supplies with disinfection only. Objectives are set and monitoring is proposed only for Quatse Lake.

Water quality objectives which are based on approved BC water quality criteria are proposed for microbiological indicators, turbidity, dissolved oxygen, pH and phosphorus. The objective for colour is based on the Canadian Drinking Water Guidelines.

MONITORING RECOMMENDATIONS

The following tables provide a summary of the objectives data and monitoring recommendations.

To protect water uses in a water body, objectives specify a range of values for characteristics (variables) that may affect these uses. These values are maximum and/or minimum values that are not to be exceeded.

Some readers may be unfamiliar with terms such as: maximum concentration, 30-day average concentration, 90th percentile and not applicable (NA). Maximum concentration means that a value for a specific variable should not be exceeded; 30-day average concentration means that a value should not be exceeded during a period of 30 days, when five or more samples are collected at approximately equal time intervals. The term 90th percentile indicates that 9 out of 10 values should be less than a particular value. Not applicable (NA) means that water uses are not threatened for that particular variable.