abstracts for
3 Victoria Sewage

The Second Annual Report of the Macaulay Point Outfall Monitoring Program presents data and interpretation for the period 1 July, 1971 to 31 July, 1972. This period covered the time during which discharge of sewage was diverted from the old shoreline Macaulay Point outfall to the new 6000 ft. outfall. Data collected since May, 1970 is also used in interpretation of seasonal trends.

At the old outfall there was rapid and complete return to background values for all parameters measured, while at the stations close to the diffuser of the extended outfall there has been no detectable change in values of all parameters except one, coliform bacteria. These showed slightly elevated levels, most frequently located within the area extending 1/2 mile to the east of the diffuser. However, values there exceeded the level of 1000 MPN/l00 ml on less than one third of sampling occasions.

Surfacing of the effluent field discharged from the extended outfall was common during most of the post-discharge period. This conclusion is based on observations that water column stability was not well established in the area and that there was frequent presence of particulate matter on the surface that could be identified as of sewage origin by virtue of associated high coliform counts. However, the amount of this material was small and did not constitute a significant degradation of the environment. It was these particles which apparently served to attract the small aggregation of gulls often sighted in the area of the diffuser.

A technique was developed for sampling sediment coliform bacteria in the deep water around the diffuser. Significant differences were found between samples obtained at the diffuser and those obtained 1/2 mile seaward of the diffuser. This technique will allow monitoring of the cumulative effect of sewage discharge, particularly valuable as discharge rates increase.

A submersible survey documented conditions near the diffuser for comparison with data to be collected after several years of continuous discharge.

A dye study tracked the highly diluted sewage field to a point two miles to the east of the diffuser, but even with a strong onshore wind there was no evidence that the field reached the shore.

Visual surveys of the shoreline adjacent to the Macaulay Point area have not shown the presence of sewage materials that could be attributed to the new outfall.

Data are presented from the Macaulay Point Outfall Monitoring Program for the period 1 March 1972 to 31 May 1972. Of the standard physical, chemical and biological parameters measured, only total coliforms indicated the presence of effluent in the waters surrounding the Macaulay Point outfall.

A rhodamine dye study could trace the surface field 2 miles to the east of the diffuser, and did not indicate any movement of the field onto the shore.

Sediment coliform levels around the old Macaulay Point outfall were found not to be different from those at control stations at Albert Head.

A shoreline sewage survey did not show the presence of sewage on the shore which could be attributed to discharge from the extended Macaulay Point outfall.

The Fifth Quarterly Data Report of the Macaulay Point Outfall Monitoring Program presents data spanning the period of commencement of sewage discharge from the new extended outfall.

The water quality tests showed that a return to baseline values near the old Maoaulay Point outfall required from 3 to 7 weeks. Total coliform bacteria counts had fallen to less than 500 MPN/100 ml near the outfall on the final reported sampling date. No discernible effects of discharge from the new outfall have been found at offshore stations to date.

Preliminary tests of a new profiling technique showed that chlorophyll levels were high in enclosed areas and close to land projections. Shallow water, high nutrient inputs and possible stirring up of bottom phytoplankton may have been the factors involved. No direct influence of sewage discharge was detected by this method. However, Carbon-14 studies suggested that outfall water may have had some detrimental effect on the photosynthetic efficiency of phytoplankton.

Sediment coliforms were high around outfalls and appeared to outline the range of the plume during a tidal cycle.

Air photo interpretation and supplementary intertidal surveys prior to cessation of flow from the old Macaulay Point outfall suggested that fewer species of marine algae inhabited the area near the outfall as compared to control areas. This may have been due to the lower salinity water present near the outfall as a result of sewage discharge.

This first annual report of the Macaulay Point Outfall monitoring program gives pre-discharge environmental and biological data. These will serve as baselines with which post-discharge results can be compared, and thus effects of the extended outfall determined.

Specifically the report includes:

1. Tabulated results of all routine water quality tests made on 26 sampling days spaced at 2-3 week intervals from May 19, 1970, to July 12, 1971 (Appendices III-VI).
2. Plots of the results of each routine test showing the annual variation in 1970-71 with an interpretation of each test's significance for the area in the light of available oceanographic information, and possible changes which might be induced by the extended sewer.

Results obtained, in general, fit within expected values for the area according to previous oceanographic and biological information, although certain peculiarities with implications for determining sewage effects are worth noting. These are:

1. The variation in physical parameters measured appears to be determined mostly by meterological conditions, with the breakdown of summer stability towards the end of October, and spring re-establishment in April. The sewage plume is least likely to surface during summer stable conditions, and thus frequency of surfacing will be determined to some extent by summer weather.
2. The nutrients indexed appear not to be the factors limiting phytoplankton upgrowth locally. This conclusion has the implication that nutrients indexed from the new outfall may produce no discernable effect on Chlorophyll A levels in the monitored area.
3. The existing sewage discharge affects coliform counts, nitrite and phosphate. These indices should be useful in locating the new sewage feld.
4. Tidal currents have important effects on the index values, and the pattern of tidal effects should be established for its predictive value in the future.

Data obtained by the Capital Regional District in 1976 from a benthic survey at the Macaulay Point outfall and the site of the proposed Clover Point outfall have been analysed.

Faunal differences between sampling stations are detectable by the analysis used in 1976 the fauna closest to the Macaulay Pt. outfall discharge point was diverse and abundant, and not significantly different from surrounding sampling stations. In 1972 the fauna had been shown as demonstrably different at the outfall. A smaller survey in 1988 also demonstrated an unusual benthic fauna at the outfall discharge point dominated by species of nematode and polychaete worms. These are known to occur on seabeds with high organic loadings. If this characterising fauna was present in 1976 it presumably occurred over such a small area that it was not sampled under the tidal and current conditions existing at the time.

Many new methods of surveying the benthos to demonstrate impact from waste discharges have been developed in recent years, and the changes in procedures continue. One or more available methods should be able to demonstrate more accurately than in 1972, 1976 and 1988 the nature and extent of seabed biological impact from sewage discharges at the Macaulay and Clover outfall discharge points.

It is recommended that the benthos be resurveyed, utilising modern techniques, to demonstrate the nature and extent of sewage impact. The results will provide information for decisions about the need for, the type, and extent of sewage treatment in the area. The new survey design and method of data analysis adopted should be determined at the time the survey is authorised.

This document presents an analysis of sediment chemistry data collected in December 1993 in the vicinity of the Macaulay Point outfall. Seventeen metals and five chlorinated benzene compounds were analyzed at 41 stations.

Temporal comparisons were made against 1992 data from collocated stations. In addition, the concentrations of metals and 1,4-dichlorobenzene were contoured and compared with sediment quality guidelines to estimate the area of sediment impact as well as the depositional pattern.

Relatively few statistically significant increases or decreases were noted in contaminant concentrations from 1992 to 1993. The most notable difference occurred at the outfall (MO) where the mercury concentration decreased from a geometric mean of 0.97 mg/kg in 1992 to 0.16 mg/kg in 1993.

1,4-DCB was the only contaminant analyzed with a geometric mean concentration (n=3) in excess of the sediment quality guideline of 110 ug/kg, dry weight. Exceedances were measured at eight stations: at the outfall (1,422 ug/kg), and at 100 m east (275 ug/kg), west (187 ug/kg), southwest (453 ug/kg), northwest (121 ug/kg), southeast (313 ug/kg), and northeast (185 ug/kg) of the outfall, and at 200 m southeast of the outfall (123 ug/kg). As defined by these stations, the impact area in 1993 was relatively symmetric around the outfall with an east and west emphasis and was contained within approximately 200 m of the diffuser. When normalized to total organic carbon (TOC) (assuming 1993 TOC concentrations are similar to those measured in 1992), however, only two exceedances were measured (at the outfall and at 100 m southwest).

In contract to 1992, when mercury exceeded the sediment guidelines, none of the metals had geometric mean concentrations greater than their respective sediment guidelines in 1993. However, 10 stations conained individual replicate samples which did exceed the guidelines for Cu, Hg, Ag, Zn, or Pb in 1993. Most of the metal contamination appears to lie along the east and southeast transects from the outfall, although a southwest spread was also observed for some metals.

Based on the results, as well as chemical and toxicological testing in 1992, a sediment monitoring program sampling design is proposed with recommended stations, analyses, and tests for future monitoring of sediment chemistry, toxicity testing, and benthic community analysis.

During May, June and November 1979, a marine environmental assessment of the Macaulay Point Sewage Outfall, Victoria, British Columbia, was conducted. Physical, chemical, biological and bacteriological analyses were performed on water, biota and sediment samples obtained in the vicinity of the outfall terminus. In addition, submersible diving observations were undertaken. The environmental impact of the discharge is reviewed in this report. Generally, the studies revealed that the discharge of raw sewage had a measureable but localized effect.

Salinity, temperature and dissolved oxygen did not differ substantially throughout the study area. Dissolved nutrient levels, specifically ammonia, were elevated at the point of discharge and declined with increasing distance from the outfall. Nitrate and orthophosphate concentrations did not significantly differ between stations.

Elevated surface sediment trace metal concentrations were confined to a relatively narrow zone adjacent to the outfall. Maximum levels of copper and lead were observed at the outfall termius during November.

Bacteriological analysis of the sediments detected coliform bacteria (sewage indicator organisms) up to 2500 m from the outfall. Total coliform and fecal coliform bacteria were found to be the most sensitive microbiological indicators of sewage effluent in the marine sediments.

The sewage discharge appeared to have negligible impact on the natural substrate with the exception of a black, organic accumulation detected near the broken diffuser.

Benthic infauna and epifauna were not present in the direct discharge stream but Pagurus sp. (hermit crab) was dominant at stations further from the outfall. Species diversity was low throughout the study area. The tissue trace metal levels of mercury, lead and cadmium were higest in the bivalve, Chlyamys sp.

The Clover Point sewage field was detectable in the receiving area by high nitrite and phosphate values, by high total and fecal coliforms in samples from both surface water and sea bed deposits, and by high turbidity levels using a towed in situ transmissometer. Extent of the sewage field was best delimited by turbidity profiling with records interpreted by water sampling for coliform analysis. This technique demonstrated drift of the particulate sewage field accompanied by high coliform levels to distances of at least 1600- 2000 feet from the outfall. Further testing of the newly available instrument might have demonstrated slightly more extensive drift, and provided more detailed interpretation, but time available precluded further work in 1971. Supporting data on extent of the field was obtained by sediment and surface water coliform analyses. High fecal coliform values in sediments from 2000-2500 east and west of the Clover Point sewer, showing a pattern of gradual reduction with distance from the outfall, indicated accumulation on the sea bed of coliforms by deposition in some way from the dispersing field. Surface water samples gave occasional high total and fecal coliform values at distances from 2000-5000 feet. The field, when detectable, was present essentially at the surface, with a vertical extent of 6-10 feet recorded by transmissometer and divers' visual observations.

The Clover Point sewage field thus appears to disperse to levels which are not detectable by a series of routine indicators including coliforms over distances from 2000-5000 feet downcurrent from the outfall. The actual direction is to east or west depending on tidal currents. These currents also restrict the field to dispersing relatively close to shore, i.e. 200-400 feet at Clover Point, but not always impinging on the beaches to east and west of Clover Point.

Shoreline biological surveys showed a slightly lower algal species diversity than at an Albert Head control station, but the reduction in number of species is relatively small compared to that recorded at the adjacent Macaulay Point beach outfall, and may be without significance in this context. An analysis of this point is continuing. Underwater biological surveys off the outfall showed no significant biological differences from expected algal growths and macrofauna, but considerable sewage debris (papers, rags) etc.) to depths of 50 feet, approximately 200-400 feet offshore.

Chlorophyll standing crops tended to be high close to Clover Point relative to levels offshore, but a surface chlorophyll-profiling technique showed similar increases at other nearby promotories without sewage discharges. Hence the high chlorophyll levels cannot at present be directly related to the sewer. A test of C14 /Chlorophyll assimilation ratios suggested low production in the sewage plume close to the sewer in spite of high chlorophyll values. This test suggests a possible deleterious effect of the effluent in high concentrations.

Sediment macrobenthic collections suggested a slight faunal change on approach to the sewer, but the technique cannot be properly applied to the Clover Point area in view of the strong tidal currents, steep slope to the sea bed and stony deposits preventing effective quantitative collecting with the sampler available.

The biological observations in toto indicate that the Clover Point sewage discharge has had little effect on species diversity in the area. However, the C14I Chlorophyll assimilation ratio tests suggest possible effects of the effluent on biological production in the local ecosystem. This aspect could bear further investigation.

There are considerable local small-scale variations in water mass characteristics (temperatures and salinities) in the broad area, from Esquimalt Harbour east to Trial Islands, surveyed in 1971 by the combined Macaulay Point and Clover Point investigations. Any persistant pattern of differences throughout the area, however, was not apparent from the procedures employed in 1971.

Filtered, untreated domestic sewage, when added to phytoplankton or fixed, brown algal cultures resulted in changes in photosynthetic capabilities. Photosynthetic carbon per unit biomass was determined by Carbon14 uptake/mg chlorophyll for phytoplankton and by Oxygen production/mg dry weight for fixed algal cultures.

Fixed and planktonic algae responded to additions of domestic sewage in a similar fashion. Low concentrations of filtered sewage (1-10 ppt) resulted in increases in photosynthesis per unit biomass while higher concentrations (50-100 ppt) caused a reduction in photosynthesis per unit biomass.

Phytoplankton culture assimilation ratios increased 7 to 206% above controls in low concentrations of filtered sewage and relative decreases below the maximum value for higher concentrations of filtered sewage. One culture showed a drop below control assimilation ratio. Concentrations of filtered sewage at 50 ppt caused variable results depending upon the culture.

Fixed algae showed increases in photosynthetic rates in cultures containing 1 and 10 ppt filtered sewage but these were not statistically significant. Cultures containing 50 and 100 ppt filtered sewage yielded a significant decrease in photosynthesis per unit biomass but there was also a decrease in control culture photosynthesis.

Both procedures provide responses of sufficient magnitude, especially at high levels of sewage effluent, to have potential as bio-assay techniques. Development is continuing on the use of the fixed algae as bio-assay organisms but further development of the phytoplankton bioassay technique, although promising, is temporarily suspended due to completion of the funded program.

This document reviews methods for monitoring the effects of marine outfall discharges on subtidal hard substrates, with specific focus on techniques applicable off the Clover Point outfall. It was completed by literature search and interviews with staff from Canadian and U.S. agencies and the private sector. The challenge was how to monitor the nature, spatial extent, severity, and cause of impacts on biological communities at >60 m depth on current-swept, rocky bottoms where traditional sediment monitoring are not feasible. A number of monitoring options were evaluated within the context of a fully integrated program, including:

• use of the resident horse mussel (Modiolus modiolus) as a biomonitor
• grab sampling for biota and sediments
• deployed monitors such as Semipermeable Membrane Devices (SPMDs)
• remote surveillance by deployed camera or Remotely Operated Vehicles (ROVs),
• precise in situ quantitative epibiota sampling.

A summary matrix table with subjective methodology rankings is provided (Table 2). In addition, specific choices for an integrated monitoring program are suggested (Table 3).

The depth and currents severely limit precise in situ methods. Remote methods which permit a level of quantitative sampling are recommended. For example (chemical-toxicological testing), tissue (Modiolus or SPMD) and biological community (still or video photography, quadrat samples, settlement panels) monitoring would provide a satisfactory integrated approach.

Monitoring designed specifically for Clover Point would break new technical ground, based on our review, as there is no precedent in the literature or among other agencies for monitoring sewage pollution under such conditions. In this context, and given the similarities between the Clover Point and Macaulay Point discharges other than the difficulties of sampling at the former, the CRD should consider focusing monitoring in the Macaulay Point receiving environment rather than the probably less affected (EVS, 1992a) Clover Point receiving environment.

The analysis of the available pre and post-extension coliform data for the Clover Point Outfall indicates that the outfall extension has resulted in significant reductions in coliform concentrations along the shoreline in the vicinity of Clover Point.

Median total and fecal coliform concentrations for 1981 are well within swimming standards for the shoreline stations monitored by the CRD Engineering Department for the shoreline between the Dock Street breakwater and Harling Point. However, the shoreline east of Clover Point is subject to periodic high coliform counts likely originating from shore sources.

The median fecal coliform concentrations for samples collected by the CRD Health Department in 1981 generally agree with the Engineering Department data. Stations west of Clover Point to the Dock Street breakwater are well within swimming standards and the pollution warnings have been lifted. Stations east of Clover Point, including Ross Bay, Gonzales Bay and Shoal Bay remain posted with pollution warnings as they do not consistantly meet the Ministry of Health swimming standards based on a five sample logarithmic average. The annual mean fecal coliform concentration is within the 200 fecal coliform per 100 millilitre swimming standard but the stations exhibit even higher sporadic coliform concentrations than those recorded by the Engineering Department.

Because the Health stations are closer to shore than the Engineering shoreline stations, the higher sporadic coliform concentrations noted in the Health survey is further indication of shoreline coliform sources. It is recommended that an investigation be undertaken to identify, quantify and if possible remedy the shoreline coliform sources along the south coast.

Samples collected from various depths at the post-extension offshore monitoring stations indicate that outfall effluent dispersing towards the shoreline from the outfall terminus is generally well mixed throughout the water column. Some evidence of effluent plume trapping was noticed during periods of high temperatures.

Effluent dispersion from the outfall terminus in directions parallel to the shoreline or offshore could not be determined from the data collected.

It is recommended that the outfall performance monitoring be continued until the end of the one year program, at which time the data should be reviewed for seasonal trends.

The purpose of this survey was to determine if the composition of the Fucus epifauna changes with varying distance from the shoreline discharging sewage outfall at McMicking Point, Victoria, BC A seasonal effect was also studied by sampling in both January and April 1982.

The results of this study provide additional data to the shoreline study by Emerson (12). Emerson's study is part of an environmental impact assessment by the Capital Regional District (CRD), required by the Pollution Control Board. The Pollution Control Board issues permits for discharging sewage. Approval of extension of the McMicking Point outfall into the middle of Enterprise Channel by this board is necessary. The extended outfall will discharge only comminuted but otherwise untreated sewage because the receiving area is well flushed by tidal currents. The area receiving sewage from either one of the Greater Victoria municipalities is greater than that property. Therefore the CRD is the responsible governmental agency to plan sewage disposal policies and to meet the requirements of the Pollution Control Board in the Greater Victoria area.

In the scope of the environmental impact assessment, a number of studies have been carried out. The results of some are presented to sketch the impact of sewage on the area. Dye releases in the area show that the coliform counts near the shoreline discharge point will improve but that elsewhere only minor changes can be expected. Trace metals and organic contaminants in sewage and receiving area have been identified at levels typical of a city with no major industry and thus only domestic sewage. Elevated, compared with a control staion, concentrations of pesticides, however, were found. Histopathologically, the mussel Mytilus californianus has been found to be in poor health near the outfall.

Samples of Fucus (8 litres) were taken at the same shoreline stations as those used by Emerson (12) so as to make comparison possible. All stations were sampled once in January 1982. Replicate samples were taken in April 1982 at a test station (near the outfall) and at a control station (600 m distant from the outfall). The epifauna was extracted from the Fucus. All organisms of the January series were identified. Of the April 1982 series only the amphipods, isopods and chironomids were identified.

The January results show that the effect of sewage is small; there is no totally different community near the outfall. Diversity based on the number of species and the number of species was slightly lower at the outfall. Sewage effects also seem to be very localized; the similarity of two stations near the outfall, only 15 m apart, based on Jaccard's coefficient, was low. The similarity of test and control stations was low, as was expected.

The April results show changes in abundance, significant with 90% confidence with both a parametric and non-parametric test of the following species: Dynamenella sheareri, Hyale frequens, Paraclunio alaskensis, and Saunderia marinus (this last species only using the parametric Student's t test). Increased counts near the outfall of Dynamenella sheareri are not confirmed by Emerson's data (12), but fit with the January 1982 results. Decreased counts near the outfall of Hyale frequens and increased counts near the outfall of the chironomid species Paraclunio alaskensis and Saunderia marinus fit with Emerson's results (12). These trends, however, were different from those of the January 1982 series, which can point to a seasonal influence on the abundance of these species.

Some changes have been found in the abundance of Fucus epifauna species in reltion to the outfall. Replicate sampling is a useful tool to prove this. Some of the effects seem to be subject to seasonal influence.

Samples of two species of mussels (Mytilus edulis and M. californianus) and sediments were obtained from the area near the McMicking Point sewage outfall, Victoria, BC Controls were obtained from the Chatham Islands group, several kilometers from the outfall.

Chemical analysis of mussels indicated that those from the area of the outfall had higher levels of several chlorinated hydrocarbon pesticides (lindane, DDE, methoxychlor), PCB's (Arochlor 1254) and phthalate ester plasticizers (di-n-butyl, and bis (2-ethylhexyl)) than were found in the control organisms. The mussels also had elevated levels of lead and mercury but decreased levels of cadmium. In addition, analysis of the sediments obtained 200 to 300m from the outfall indicated that concentrations of pesticides (hexachlorobenzene, lindane, DDE and methoxychlor) PCB's (Arochlor 1254) and phthalate esters (di-n-butyl, butyl benzyl and bis (2-ethyl hexyl)) were elevated over those found at the control site. Concentrations of lead, copper and mercury were also elevated in the outfall area.

Histopathological examination revealed that Mytilus edulis from 15m west of the McMicking Point sewer outfall were in poor condition as indicated by: significant degeneration of the reproductive tracts, digestive tracts, kidneys, pericardial glands, and muscle tissues; depletion of nutrient stores; inflammation of tissues; and parasites in all 20 mussels examined, at low to high levels. Mytilus californianus from 50-l00m west of the outfall were in fair condition with slight digestive degeneration, kidney concretions, inflammation of tissues, and with parasites in 3 of 20 examined but at very low levels. Mytilus edulis from the control site were rated as in only fair condition since parasites were found in all 20 mussels examined but at low levels; otherwse, tissues were in good condition. Mytilus californianus from the control site were in good condition but with parasites in 10 of 20 at very low levels.

Report 1: Final Report: Sanitary Aspects proposed McMicking Point Outfall

The Capital Regional District contracted Willis, Cunliffe, Tait & Company, Limited and Daniel, Mann, Johnson, & Mendenhall to perform oceanographic studies for a proposed outfall terminating in the centre of Enterprise Channel to replace an existing shoreline discharge at McMicking Point. Specifically, the purpose of the study was to recommend an outfall route and discharge point and to describe the fate of sewage released from the selected point. Due to cost considerations and public preferences, this gravity flow outfall would be much more acceptable to other sewage removal plans if the outfall is feasible.

All predictions are based on an average sewage flow rate of 15 cubic feet per second in year 2015, a maximum sewage flow rate of 19.2 cubic feet per second in year 2015, and a minimum sewage flow rate of 4.0 feet per second in year 1981. Design maximum coliform levels in sewage were set at 50xl06 per 100 milliliters, with average levels set at 33x106 per 100 milliliters. Comminution of the sewage is planned, but no pumping capacity is considered as part of the criteria.

Hydrographic surveying was used to establish the probable construction scenario and route. The selected plan was for installation through South Kitty Inlet to the deepest part of Enterprise Channel. The recommended route extends for about 700 feet in water. Diving reports in the area confirm the information gained from this survey.

A series of field tests were conducted to determine the performance of the proposed outfall. Included were surface, mid-depth, and bottom current measurements, temperature and salinity data collection, and dye dispersion studies utilizing both batch and continuous reease methods. When combined, the information portrays clearly the general physical characteristics affecting sewage dispersal in the area. Also, theoretical models of various dilution phenomena were considered and compared with the dye data.

The point at which effluent reaches the sea surface is expected to be up to 61 feet downstream from the release point. The average time for surfacing of the sewage after discharge is about 11.7 seconds. Based on the selected outfall terminal site, the "Initial Dilution Zone" to be considered in future studies will most likely extend only 150 feet horizontally in all directions from the point of release.

The area of coast between McMicking and Gonzales Points will be "cleaned up" substantially. The zone, now affected directly by an effluent plume at flood tide, will receive only well-diluted sewage from the new outfall except in unusual cases. A median coliform MPN is expected to be less than 1,000 per 100 milliliters, which is the general standard. The area between McMicking Point and Kitty Island will experience relatively high coliform levels during slack tides, as well as return flow from upstream effluent discharged during the previous tide. All factors considered, the median MPN for coliforms is expected to range from 2,500 to 5,000 per 100 milliliters. West of Kitty Island, and in McNeill Bay, little change in effluent dispersion is likely by establishing a new outfall. Based on year 2015 flows, the median coliform MPN is predicted to be between 1,500 and 2,000 per 100 milliliters. No significant sewage levels are expected around the Trial Islands from the new discharge.

Floatables affecting the shorelines will be reduced substantially although not totally eliminated by use of the proposed outfall. Any floatables reaching the shore will usually do so under the influence of a southeast, south, or southwest wind.

Use of a diffuser will improve pollutant levels in the Channel centre but will likely create higher coastal coliform MPNs since some of the dischage jets would have to be closer to the shore. Thus, a diffuser is not recommended, unless the design criteria relating to general location and pumping capability are altered.

Report 2: Final Report- Constriction Aspects proposed McMicking Point Outfall

This second report presents the findings of studies to determine the physical feasibility of designing and constructing an outfall into Enterprise Channel. To perform these studies, surface and bottom current measurements and underwater geological diving investigations were conducted along a preselected route through South Kitty Inlet to the deepest part of the Channel. The highest bottom current speed recorded was 4.26 feet per second at the deep water end of the route. Lower current speed maxima were detected inshore of the proposed terminus. A gravel cover over soft clay was indicated along most of the route. Sand over clay and bedrock was found about halfway between shore and the end of the route.

Current and wave conditions were analyzed to develop design particle velocities for the life of the outfall. The design velocities calculated were 9.4 feet per second nearshore and 11.1 feet per second at the deep water end of the route. These values were used to determine stability requirements for a 42-inch steel pipe with a 0.750-inch wall thickness. Assuming a circular configuration around the pipe, six and one-half inches of concrete with a density of 190 pounds per cubic foot would be required to provide in-situ stability.

This configuration is achievable, so the project is considered feasible, although construction will be difficult and risky. A study of alternate methods for providing stability should be performed in the design phase of the project. The bottom pull method may be the best for construction; however, the actual method used should be selected as design is completed.

The report presents a photographic and underwater survey of the main biota in the McMicking Point area. The study is basically a qualitative one although notes on abundance were made. Species diversity between sites was compared based on the number of species present. The study was done to establish a baseline to compare changes which might occur after relocating a sewer outfall in the area.

The results of this study demonstrate a definite relationship of species diversity with bottom type. Therefore, the bottom types in future studies should be examined separately to determine qualitative changes in each of these types. Comparison of this study with the study done by Emerson and Kashino in 1979 brought to light several discrepancies in species composition which are probably due to seasonal changes in the benthic community. Therefore, it is recommended that future studies be carried out within the same month.

Amphipods may be indicative of the detrital load due to the present outfall. During this survey bottom samples were additionally taken with a hand held corer at each of the stations where possible. Examination of the samples taken at these stations during this study would provide more accurately a record of the amphipod population of the study area and any changes which may occur.

The obvious litter bed along line D should be an indicator of the effectiveness of the new outfall and a marked decrease of litter in the line D area is expected.

The Environmental Impact Assessment for the McMicking Point Sewer extension should proceed in three phases. A preliminary intensive testing period (Phase I) is needed to identify kinds of impacts liable to occur and to start assessment of the present state of the environment. This should be completed and reported on by December 1978. Monitoring should be continued until the extension becomes operational (Phase II) about September 1979. Impact assessment of the extension (Phase III) will take at least a further year thereafter.

The Phase I environmental impact assessment should include:

1. Chemical and microbiological testing of the sewage to determine the nature, toxicity and variability of the materials being discharged to the sea,
2. A survey of the current patterns in the receiving area so that sewage dilution, dispersion and possible points of impact on shore can be predicted,
3. An assessment of the present state of the environment in the proposed discharge area particularly testing for impacts arising from the present shoreline discharge
4. An assessment of the various social sources of contaminants within the sewage, and the present, potentially alterable, social use of the receiving area.

The previously submitted recommendation for the required monitoring program has been reviewed with scientists at four major U.K. environmental laboratories. These reviews support the scope of the testing, but suggest that fewer repeats should be sufficient to predict and control environmental impact.

A testing program now specified in cost at $123,580, just less than half the original maximum estimate of $249,896, should allow assessment whether impact of the extended outfall will meet requirements of the B. C. Pollution Control Act. This could be completed in November 1978 if authorised now, subject to the possibility that the impact of winter storm conditions on sewage dispersal might need assessment.

Alternatively the impact assessment can be authorised in three overlapping stages costing $49,050, $43,530 and $31,000 respectively (total $123,580). The first stage should be authorised June 7 (and ratified by the Board June 14), the second stage should be authorised in early July and the third stage in early September. Assessment could be complete by January, 1979. Later authorisation would mean that critical seasonal conditions would be missed, with delays in impact assessment possibly extending up to a full year.

Costs of the impact assessment are potentially fundable by government grants. Costs may be shareable between engineering and environmental budgets, and between environmental budgets for several outfalls.

A series of projects conforming to the concepts of the Mussel Watch have been in progress in British Columbia for some years. Since 1970 marine bivalves and other organisms have been monitored for seven metals in Rupert Inlet, the marine receiving area for tailing from Island Copper Mine. Mussel transplant experiments were initiated in 1978. Lesser programs at the Wesfrob Iron Mine at Tasu, Queen Charlotte Island, and the Jordan River Copper mine on Vancouver Island were started in 1970 and1972 respectively. A substantial testing program for metals was initiated in 1974 at the northern mainland Inlet, Alice Arm, the site of a proposed reopened molybdenum mine.

Metal testing was initiated in 1970 around the discharges of pulp mills using a zinc based bleach in and near the Straits of Georgia (e.g. Crofton) and has continued intermittently even following withdrawal of the bleach in 1973. Metal testing has also been initiated in 1979 at a sanitary sewer, McMicking Point, in the Victoria region, and in the Fraser Delta where contaminated organisms support a number of relevant research, as opposed to monitoring programs. A proposal to continue such testing at the Victoria site for an expected three year period is in operation. This project will also test periodically for chlorinated hydrocarbons and other organic materials in mussels. Testing of mussels and other bivalve molluscs for fecal coliform bacteria has been implemented irregularly at a number of sanitary sewers and waste seepage sites in the Victoria district, e.g. at Macaulay Point and Ganges Harbour. A program at the latter where an outfall is planned is expected to continue for a 2-3 year period.

The kinds of sites which lend themselves to mussel watching in BC are hose which dispose of metal-bearing wastes (mine-mills), industrial organic wastes (pulp and paper mills) especially those which utilise chlorination and nitrogen enriched processes, and large sanitary sewers such as in the areas of Victoria, Vancouver, Nanaimo, Prince Rupert, and that now proposed for Comox.

Approximately 700 tests of contaminants and other sewage parameters have been completed for the McMicking Point discharge in 1979. Some trace metals occur at low levels, some of which on occasions are higher than provincial Objectives, but these trace metals are not in quantities indicating that immediate remedial action is needed. Some organic contaminants occur at very low levels, and their significance is now being determined by literature searches.

An earlier report in 1979 documented a minor biological impact of slightly changed shoreline organisms within 20-600 metres of the existing sewer. The total information from 1979 on sewage quality and its impact supports the implicit judgements of the past that rnajor concern with the discharge at McMicking Point must be over public health, rather than biological or other environmental impact. It is noted in this context that interim design calculations for the sewer extension show that the health-related parameter, the BC shoreline total coliform standard, may not be met continuously throughout the area with predicted flows. The appropriate calculations should be made to predict whether the coliform standards, and hence contemporary public health demands, can be achieved continuously with any of the alternative lesser sewage discharges at McMicking Point.

Further data gathering and assessment at McMicking Point should be directed to determining whether there is a long-term public health or ecosystem impact from the trace contaminants in the sewage, and to completing baseline data for comparison with results to be obtained after the sewer is extended so that its effectiveness can be measured.

Monitoring in 1980 has confirmed that biological lmpact of the existing sewage discharge at McMicking Point is barely detectable at a distance of 50-100 metres from the discharge point, but can be detected quite readily at a distance of 15 metres. Contaminant tests of sewage and the limited array of available shellfish (mussels) indicate that some pesticides are discharged at minute levels to sea; at least during the annual spring garden spraying period.

The post-extension monitoring programme should consist initially of the Regional Health Inspectors tests that beach recreational-use bacterial standards are not infringed. If the Health standards are not met, the extended outfall should be recognised as inadequate for continued discharge at the existing flow rate, and an alternative sewage disposal design should be developed. If the Health standards are met, or if the outfall is commissioned too late in 1981 for the Health tests to be applied during the summer months, marine monitoring should be continued. The programme should consist of seawater bacterial testing, sewage and shellfish contaminant testing, underwater and shoreline biological surveys, fish fin-rot surveys, and shoreline litter surveys. If results show a level of litter on shore, or biological effects, derived from the extended outfall, a decision willthen have to be reached whether these effects are acceptable or not.

Since the last report in September 1980, surveys of fish fin-rot have been initiated around the McMicking Point outfall. The preliminary results do not demonstrate that the sewage-caused disease is present. More fecal coliform bacterial measures have been taken to provide additional baseline data prior to extension. They demonstrate the presence of partially dispersed clouds of sewage in Enterprise Channel. Although partially dispersed, these clouds nevertheless have levels above the recreational contact standard of 200 colonies per 100 ml water. An underwater biological survey by scuba divers has been completed as a baseline record for later comparison. It provides details of the rock bottom shallow water benthos. Attempts to collect a storm flush sewage sample for toxin analysis were unsuccessful during the spring pesticide spraying period, April through May 1981, as lack of a short intensive storm precluded an adequate storm flush sweeping roads and sewers of accumulated toxin-laden materials. This suggests that the high storm flush concentrations found in 1980 may not be a regular spring phenomenon. Mussel sampling for toxins has been extended but analyses are not yet complete. Previous weather data have been extended.

The 1980 recommendation that initial post-extension monitoring should consist of shoreline fecal coliform testing by the health authority is repeated. If beach closure is maintained, the situation should be considered unsatisfactory. The influence of the Harling Point sewer and any storm sewers should be considered and the various alternative disposal options explored.

If beach closure is lifted, seawater fecal coliform testing should be continued to demonstrate whether partially dispersed sewage is detectable in Enterprise Channel. If so the health significance to shoreline an water users now and at future higher discharge levels should be appraised.

If seawater coliform levels are satisfactory, repeat shoreline litter surveys should be implemented in summer 1982. If these demonstrate continued drift of sewage litter onto shore, ways to reduce the litter could be sought.

If the three above criteria demonstrate satisfactory sewage dispersion, then further shoreline and underwater sampling should be undertaken in 1983 to demonstrate any biological impact, with the expectation of a final report from the monitoring program in December 1983.

Continued monitoring in 1980-81 provides the minimum baseline data needed for comparing with post-extension checks of outfall capability. In general, biological impact of the shoreline discharge was slight but social impact was unacceptable.

There is some possibility that the new disposal system of an extended outfall may produce an environmental situation of dispersing sewage eddies, close to health and aesthetic criteria separating acceptable from non-acceptable, and that continued, more intensive, monitoring costing up to $100,000 or more may simply confirm this borderline situation. The multi-million dollar cost of other disposal systems for the McMicking sewage justifies continuing the monitoring. It should be noted that a clearer distinction of acceptability or non-acceptability may not be derivable from more environmental data. It appears nevertheless that a more intensive monitoring programme along lines originally recommended in 1978 is needed, and a sample design is being prepared.

This report documents the impact of the existing shoreline sewage discharge at McNicking Point on the biology of the area, especially the composition, distribution, and abundance of shoreline organisms. Impacts on other aspects of shoreline biology, e.g. the uptake and concentration of contaminants by organisms is under test by a separate continuing program which will be reported later. A survey of mussel distribution is included to facilitate obtaining specimens ot this shellfish for contarninant testing. A survey of the nature and extent of sewage borne litter is also included. ln addition this report documents underwater organisms present in Enterprise Channel along a route which preliminary topographic information indicated might be suitable for an extended outfall.

The report provides a basis for predicting changed impacts as a result of extending the sewer into Enterprise Channel, and will function as the report of baseline conditions for comparison in the event of extension.

This report primarily documents impacts of the McMicking Point sewage outfall on species composition, abundance, and distribution near the present shoreline discharge point. Species composition, abundance, and distribution reflect the important property of biological productivity, and the contribution of a particular area to the overall value of the sea as a renewable resource.

The shoreline near the existing MoMicking Point outfall shows minor biological changes from the normal range of conditions. In spite of considerable litter deposits, and litter and turbidity in the water drifting along shore, the species composition at the outfall was in almost all caseswithin limits present at adjacent control stations, and within descriptions of normal rock shore situations elsewere on the Southern Vancouver Island coast over a 30 year period. However, a detailed survey of one specialised component of the ecosystem, the epi faunal organisms of the shoreline rockweeds (Fucus distichus) did show some abundance changes. In this habitat species abundances near the outfall were raised for three (possibly four) species and lowered for two species out of approximately 40 species identified. Overall diversity of this community was increased near the outfall. The effect on the various species extended varying distances from 20m to 600m. The effect is so limited in nature and extent that we cannot conclude it contributes to serious losses of biological productivity. Other such species changes might have been found with more detailed surveys, and it is to be expected that similar species compositional changes occur on the rocky habitat underwater in the immediate vicinity of the shoreline discharge point. An extension of the outfall into Enterprise Channel should so improve dilution that the detected level of impact on shore should be reflected and should not recur elsewhere nearby. There may be a similar minor impact in the immediate vicinity of an underwater discharge point, but it would be extremely difficult, if not hazardous, to monitor such minor and limited species associational changes in such a habitat.

Contaminant uptake and accumulation by shoreline species, and consequent reduced viability of individual organisms, will be reported later, but it should be noted that if such an impact is occurring the toxicant accumulation has not poisoned sufficient number of organisms over a 66 year period of sewage discharge to significantly change the species composition and distribution of shoreline organisms. Contaminant uptake, however, if it is occurring, has implications for human health and therefore must be monitored.

Litter affects the quality of the environment for the public and contributes to health risks in obvious ways. These surveys provide a measure of the litter on adjacentbeaches and indicate those amounts that are derived from the sewer. Litter is obvious within 200m of the Point, and is mostly from the sewer. Some litter nearby arises from other sources which will not be controlled by action at McMicking Point.

An underwater survey in Enterprise Channel demonstrated an abundant and diverse ecosystem within the limits to be expected in the Southern Vancouver Island area for such a gravelly-rocky fast water habitat. The species present are documented by this report, providing baseline information for resurveying in the event of outfall extension. Supplementary surveys will be needed particularly if the outfall route is substantially different from that deemed most suitable at the time of this survey, and to monitor the development of a sludge bed. Our results indicate that the existing shoreline sewage discharge has no obvious impact detectable by visual survey on underwater species composition and distribution at a point some 200m to the west.

At the present time we conclude that impact of McMicking sewage on the biology of the area nearby is slight, and insufficient for us to object to extension of the outfall as a pollution control measure.

The data base for the chemical monitoring program at McMicking Point outfall was expanded to six stations for organic contaminants and to four stations for trace metals. In general the same trends were noticed as in 1980, with many organic and inorganic contaminants showing elevated levels in the immediate vicinity of the outfall and decreasing with distance away from the outfall.

The trace metal values showed good reproducibility, and the levels were generally consistent with the 1980 data. The organic data showed a similar pattern of contamination to that reported in 1980, but variations of up to an order of magnitude in the absolute values. A better measure of statistical variability will be required to monitor temporal changes in the absolute levels of organic contaminants.

Thirteen sewage samples taken from McMicking Point outfall by CRD personnel, were analysed for chlorinated hydrocarbon pesticides, PCBs and phthalate esters. Two pesticides, lindane and hexachlorobenzene, were detected in nearly all of the samples at levels ranging up to 42 ng/L (parts per trillion) for lindane and up to 2.3 ng/L for hexachlorobenzene. Methoxychlor was detected in trace amounts in six of the samples and at 59 ng/L in one sample. PCBs were detected in three samples at 7 to 16 ng/L. Four of the common phthalate esters were detected in all but one of the samples, with total concentrations ranging from 2.7 to 16.4 ug/L (parts per billion).

Two sewage samples, obtained by CRD personnel under the supervision of Seakem Oceanography, were analysed for saturated and polycyclic aromatic hydrocarbons, chlorinated hydrocarbon pesticides, and phthalate ester plasticizers. The levels of all compounds monitored were considered to be very low and to present no significant environmental hazard. The nonpolar hydrocarbons, in the 1 ppm range, were composed partly of petroleum products but mainly of biogenic hydrocarbons. Polycyclic aromatic hydrocarbons were found to be below the 1 ppb level. Low levels of only two pesticides were detected; lindane at 0.1 ppb, and methoxychlor, in the June sample only, at approximately 0.26 ppb. A number of common phthalate ester plasticizers were detected with the maximum of any one being 20 ppb.

Seawater samples were collected from the three stations within McNeill Bay and analysed for fecal coliform concentrations. The samples were taken over various tidal cycles on nine separate occasions during the months of November and early December 1982.

The results of the fecal coliform analyses indicate that McNeill Bay is influenced by effluent originating from the McMicking Point outfall. The outfall plume initially moves from east to west across the mouth of the bay during ebb tides before being drawn into the bay. Subsequent mixing results in elevated fecal coliform levels within the bay. Coliform concentrations up to 4400 fecal coliforms per 100 millilitres (FC/100 ml) were recorded during the study, although the majority of samples were below 1000 FC/100 ml during ebb currents. Flood currents resulted in an overall decrease in fecal concentrations to levels between 20 to 50 FC/100 ml. Median and ten-percentile fecal coliform concentrations were generally above the bathing standards of 200 and 400 FC/100 ml respectively for the tides sampled.

Fecal coliform expected value plots (probability curves) are presented for the tide cycles monitored. The wide variations in concentrations, related to tide variations, makes it impossible to construct a meaningful single probability curve to represent average conditions within McNeill Bay based on the data collected.

Several recommendations are made regarding the review of the coliform data by Health authorities, and possible further coliform monitoring within the area.

This interim report of the Finnerty Cove monitoring program gives data collected from the onset of the project in June to August 4, 1971.

The observations made to date indicate that the sewage field normally disperses to acceptable coliform levels down the tidal currents running parallel to shore, but that under some environmental conditions, notably inshore winds and slack water, sewage debris might arrive onshore. The frequency of this occurring needs prediction, with an estimate of tie extent of dilution of the sewage field if it should arrive on shore.

Water quality tests and biological surveys indicate no observable deterioration of the environment, instead an area of enrichment the extent and intensity of which is still being measured.

Coliform enumeration by membrane filtration technique (MFT) was conducted for septic tank and sewered regions of Ten Mile Point and adjacent communities. Data indicated highly elevated coliform levels in septic tank regions. Parameter analysis of time, date, and site factors for septic tank regions employing a Model I three way ANOVA indicated coliform levels were variable inter-dependent. In septic tank regions daily time specific coliform counts were positively correlated as were residential water consumption and stormwater coliform levels. Downstream coliform densities were Iower than the reference sampling point.

The final report of the Finnerty Cove Outfall Monitoring Program gives data collected from June through October, 1971. Unstable density structures resulted in a well mixed water column with almost uniform values throughout the area for the water quality parameters investigated. This mixing action, created by strong and turbulent tidal currents, usually dispersed coliform bacteria to levels less than 1000 MPN/100 ml within a few hundred feet of the outfall. During slack water, of a few hours duration at most, there may be a temporary build up of the sewage field around the outfall. A test using continuous turbidity profiling equipment, showed the sewage field to extend, at the surface, some 2000-3000 feet downcurrent from the plume. Similar distance estimates were derived from results of sediment coliform determinations.

Intertidal and subtidal studies, as well as chlorophyll measurements of the water, suggest that little, if any, biological deterioration has occurred near the outfall. Some enrichment, however, appears to be occurring, but to a level which present knowledge cannot specify as either beneficial or deleterious over the long term.

An oceanographic study was carried out in order to determine the dilution and dispersion characteristics of wastewater from the Ganges sewage treatment plant on Salt Spring Island, British Columbia. The wastewater undergoes secondary treatment and disinfection before being discharged to the mouth of Ganges Harbour through a 4800 m-long outfall. Wastewater is currently discharged only during ebb tides. This study examined wastewater dispersion for the present conditions, as well as for future conditions which may involve continuous (ebb and flood) discharge and higher flows. Two sophistocated techniques were combined to enable analysis of wastewater dispersion to extremely low concentrations— these were a high-precision mapping of a tracer injected into the wastewater strearn, and a numerical dispersion model.

New field measurements were made over a 4-day period in November 1993 using a fluorescent dye tracer added to the wastewater in known concentrations. The dye concentrations were mapped in three-dimensions at the mouth of Ganges Harbour using an accurate, submersible instrument package towed behind the survey vessel. Dilution factors for the wastewater were derived from these concentration measurements. Wind measurements, moored current meter data, and drogued drifter measurements were also obtained as part of this field program to aid in the interpretation of wastewater dispersion.

The field observations showed that currents were frequently towards the north, northeast and northwest in the region of the outfall terminus, resulting in a general movement of wastewater towards Welbury Point, Welbury Bay and Scott Point peninsula. This dispersion was confined to the upper 5 m of the water column during the survey period. However, mixing occurred so quickly that the wastewater was diluted by a factor of more than 16,000 to one before reaching shore. Nearer the outfall dilutions were lower, typically confined to an area of about 0.1 km2. The minimum near-surface dilution found above the outfall was 419:1. The new data all support the existence of a clockwise eddy in the mouth of Ganges Harbour, first suggested by Simons (1979).

Three-dimensional hydrodynamic and dilution models were used to predict wastewater dispersion for different oceanographic and meteorological conditions, and to look at the difference between the ebb-only discharge and the continuous discharge. These models were calibrated and verified by accurately reproducing the measured currents—both the northerly currents at the outfall and the clockwise eddy were verified in the model simulations—and by reproducing the dye concentration distributions. Once verified the models were used to give reliable predictions of dispersion for a range of other environmental conditions.

Long-term simulations were carried out for winter and summer conditions, and for ebb-only discharge and continuous discharge. The resulting series of wastewater distributions were found to be highly variable because of the changing effects of tide and wind. These distributions were summarized in terms of 15-day average and maximum concentration maps over the study area. These maps provide a versatile method for extrapolating the model predictions to different wastewater discharge flows.

The model results show that wastewater concentrations are essentially unchanged in the far-field (e.g., Trincomali Channel, Swanson Channel) as a result of switching from an ebb-only discharge to a continuous discharge. Some increase in wastewater concentration was found at the head of Ganges Harbour and at the head of Long Harbour for the continuous discharge case; however, dilutions in all cases exceeded 500,000 to one, corresponding to concentrations well below detection limits.

1. The biological resources of major concern in Ganges Harbour are Pacific herring, juvenile salmonids and shellfish populations. The herring spawn and rear in the harbour and have supported a commercial roe fishery in recent years. There are no oyster leases in Ganges Harbour, however, oysters, clams and crabs may be used recreationally.
2. A field sampling program was conducted in August, 1978 to compare benthos, plankton and fish at the proposed outfall sites. Benthos sampling indicated the presence of an anoxic area in the vicinity of Station B (diffuser location 3000). Numbers and diversity of benthic organisms at this station and at Station C (location 2125) were depressed compared with the control station at the harbour entrance.
3. The effect of present sewage contamination of the harbour is indicated by elevated fecal coliforms within the existing shellfish closure area and in Walter Bay. Water quality outside this area meets the shellfish growing water standard of 14 fecal coliforms/l00 ml. Nutrient levels were low and within the range expected for coastal waters.
4. Potential impacts associated with the project include oxygen depletion, nutrient enrichment, contamination by pathogenic microorganisms and toxicity of wastes.
5. Assuming efficiency of the proposed treatment system, the two outer outfall locations appear environmentally feasible. Further evaluation is, however, required for estimating the effects of "worst case" situations.
6. Baseline data required for final evaluation of the proposed outfall sites are seasonal water quality measurements including nutrients and dissolved oxygen/salinity profiles and a survey of shellfish beds in the vicinity of the recommended site.
7. Pre-development baseline monitoring should also include sampling of the benthos at the proposed outfall site and the determination of background levels of fecal coliforms and other pollutants such as metals, pesticides and chlorinated hydrocarbons in shellfish tissue.
8. One of the most important factors in maintenance of water quality objectives for the protection of fish and shellfish will be the effectiveness of treatment and disinfection.

There is now considerable knowledge about the Gorge Waterway ecosystem, especially of conditions in 1966. At that time the basic hydrography was investigated to a professional level by Waldichuk, and students at the University of Victoria conducted a range of faunistic and floristic surveys. These were followed in 1967 by a study of the residual oyster stocks, and in 1968 by a study of Portage Inlet sediments.

The basic information on the structure of the aquatic environment, the animal and the plant communities is now available. There is information on population biology of one of the two major biological resources in the area, i.e the oysters, but inadequate information for management purposes on the otber main biological resource, i.e. the herring (and the eelgrass communities). Furthermore, data on the main existing biological problem, i.e. enrichment, gathered in 1966 may now be out of date and needs supplementing.

The possibility of rare species of waterfowl being dependent on the existing Waterway conditions can be checked with the ornithological section of the Victoria Natural History Society.

An additional report received after drafting this synthesis provides environmental data through 1967 and 1968.

It has been demonstrated that there were definite trends in distribution of organisms present in this survey. The factors that could possibly determine distribution were studied. Oxygen and temperature in the surface environment did not appear to have any distinct limiting effect. Salinity however appears as a definite gradient increasing from Portage Inlet where there was a low reading of 8.76 o/oo to the breakwater region where there was a reading of 32 o/oo. It was concluded that the organisms' distribution could be correlated with the salinity of the water and certain forms were euryhaline or stenohaline.

1. The distribution of larvae and adult oysters, Ostrea lurida and Crassostrea gigas was surveyed in Portage Inlet, Vancouver Island from June 11, 1966 to March, 1967.
2. The larvae of both species were recorded in highest densities at the commencement of observations on June 22, 0. lurida was recorded at 2.4 larvae per litre and C. gigas at 1.8 larvae per litre. Larval densities were reduced to zero by August 10 for C. gigas and by August 24 for 0. lurida.
3. Some spat settling was recorded from June 29 to August 24 but technical problems prevent a good quantitative assessment.
4. Living adults of both species were extremely rare in the Inlet itself in 1966. Crassostrea gigas was located in patches in the Inlet and the Gorge. Ostrea lurida was found living only in the Gorge.
5. The limiting factors to C. gigas seem to be temperature and lack of a suitable substrate. The extreme temperature and salinity range and sediment probably prevent penetration of 0. lurida higher up the Inlet. At station 1 high up the Inlet the salinity ranges from 0 o/oo to 34 o/oo and the temperature from 3 degrees C to 27 degrees C. At station 8 near the Upper Harbour salinity ranges through the year from 18 o/oo to 32 o/oo and temperature from 7 degrees C to 18 degrees C.
6. Portage Inlet is a "normal" estuary in winter, i.e. salinities are reduced upstream. In summer it is a neutral, well mixed and hypersaline estuary as a result of low run-off and evaporation.
7. Through interpolation and use of the literature it was estimated that the larvae were first released in the Gorge about May 14 when the water temperature was 16 degrees C.
8. Larvae were fairly evenly distributed in the Inlet and spat was caught at all stations. The factors which affect the adult distribution must operate at the time of settling or soon after.

Current studies were carried out in the area of Esquimalt Hargour to aid in the assessment of alternative locations for discharging treated sewage effluent. Over the period February 10-13, 1974 drift card, drogue and dye studies were carried out simultaneously at several potential discharge points both within Esquimalt Harbout and off Esquimalt Lagoon.

Strong southeast winds moved water directlly onto adjacent beaches at all stations, and winds east of north moved water within the Harbour to its western shoreline. With the other combinations of wind and tide experienced during the study period, water movement tended to be parallel to the shoreline at all locations.

Estimates of dilution factors obtained when dye moved onto adjacent beaches were between 1.3 x 10 to the 4th power and 7.5 x 10 to the 5th power.

Vertical profiles of temperature and salinity established that the water column was in general isohaline and isothermal.

Studies of the bottom and sub-bottom sediments of Esquimalt Harbour were undertaken principally during the later part of FY 1978, using a sub-bottom profiler, side scan sonar, and grab sampler with position fixing by radar. Grain size distribution was studied using a two meter settling tube and automatic weighing system, with slower methods used for comparison and verification.

The structure of the sediments in the harbour is quite complex. In particular some strong reflectors warrant further study to determine whether they are solid or gaseous.

A reasonably diverse array of shellfish (bivalve molluscs) inhabit sediment beds close to the tidal channel at hte north-east end of Esquimalt Lagoon. These include the soft-shell clam, Mya arenaria, the Littleneck clam, Protothaca staminea, and the bentnose clam, Macoma nasuta. Shells of the butter clam, Saxidomus giganteus, the basket cockle, Clinocardium nuttallii, the horse clam, Tresus capex, the mussel Mytilus edulis and Venerupis japonica were also collected. A variety of other marine organisms inhabit the shellfish beds including eelgrass and algae, polychaete worms, crabs, shore birds and diving birds. A lesser range of species occurred at the head of the lagoon near the base of Coburg spit. Almost no living organisms were collected on the seaward side of the spit at its mid-point and at its base.

The proposed discharge of sewage to the sea off Esquimalt Lagoon will have only minor impact on the marine ecosystem, will normally meet the Pollution Control Objectives for coliform bacteria, and will not be visually prominent. The Objectors amongst the assessing group withdraw their Objections to the proposal, but ask that the Capital RegIonal District be required to implement a small further pre-discharge survey on coliform levels, a post-discharge assessment for coliform levels within one month of discharge commencing, and a second more comprehensive post-discharge assessment a year later. These assessments will check that the outfall is functioning in the predicted manner.

This report is concerned with the improvement of sewage disposal facilities for Royal Roads and Belmont Park which are currently served with a septic tank with an outfall under Esquimalt Lagoon, and which discharges the effluent within 300 feet of the shoreline of the Coburg Peninsula.

Two alternatives have been investigated involving the provision of an extended aeration treatment plant and discharging chlorinated effluent into either Esquimalt Harbour, as recommended in an earlier report by Mr. Wishart, P. Eng., or under Esquimalt Lagoon into the marine waters beyond Coburg Peninsula. Neither location is desirable for a permanent ocean outfall, and the capital cost will be in the order of $451,000 to $486,000.

Since both DND and DOE have intimated that it is their intention to connect these sewage discharges into a municipal sewerage system as soon as one is available, it is felt that the timing of construction of the proposed Albert Head trunk sewer should be discussed further with the CRD. If it is possible that this trunk sewer could be provided within five or six years, serious consideration should be given to maintaining and improving the existing system, possibly by lengthening the existing outfall and renewing the cathodic protection.

If it is felt that treatment facilities must be provided immediately, it is recommended that the cheaper of the two alternatives be provided because of the short-term nature of this solution. This would involve the provision of an extended aeration treatment plant with an outfall extending under the Esquimalt Lagoon and 1,100 feet beyond the Coburg Peninsula.

It is important that immediate steps should be taken to remove storm water from the existing collection systems as this will greatly improve both the existing and possible future treatment process. It will also reduce pumping costs and capacity requirements in the municipal trunk sewer as and when it is available.

A method is devised to predict the "worst case" shore- line concentrations in the effluent field discharged from a submerged ocean outfall. Three phases in the dilution process are recognized and are combined into an empirical equation: initial dilution, turbulent diffusion, and decay. Readily obtainable environmental parameters such as wind speed and direction frequency distributions, water current speed and direction frequency distributions, and the density stratification frequency distribution are employed to predict the "worst case" concentrations and their probabilities at selected shoreline locations. The technique is applied to the Royal Roads area, a coastal embayment in the Greater Victoria area in which a sewer outfall already exists and a second outfall is proposed. In order to predict the median shoreline coliform counts for critical locations, the "worst case" values are fitted to a lognormal distribution with a standard deviation which is determined from a limited monitoring program of the existing outfall. Although the errors involved in the calculations are quite large, the technique yields an order of magnitude prediction. The method finds that the existing Royal Roads outfall meets the environmental standard of a shoreline median coliform count not greater than 1000 MPN per 100 ml. The method also predicts that the proposed Portsmouth outfall will be well within the environmental standard.

The coast of Vancouver Island, British Columbia, Canada, is indented by many bays and inlets. Reconnaissance surveys of the bottom and sub-bottom of Victoria Harbour, Esquimalt Harbour, Royal Roads, Pedder Bay, Parry Bay, Becher Bay, Sooke Bay, Sooke Harbour and Sooke Basin are reported. A 3-7 kHz profiler and 105 kHZ side scan sonar were used.

A more extensive study of Sooke Basin using a better positioning system, one meter coring equipment and divers is also reported.

During a 1-year intensive monitoring program of Esquimalt Lagoon, BC, a red tide occurred in September and October, 1978, involving the non-toxic dinoflagellate Gymnodinium sanguineum. Detailed information is therefore available for the period leading up to, during and following the red tide. A number of factors are considered with respect to their roles in initiating, maintaining and terminating the bloom, including temperature, salinity, hydrography, light, macro- and micronutrients, competition and predation. It is concluded that all phases of the bloom were regulated principally by the availability of inorganic nitrogen, although not all aspects of its development can be explained in these terms.