|
10.
Environmental effects monitoring of the robert O.
pickard environmental centre Étude de suivi dES effets sur
l’environnement dU centre environnemental Robert O. pickard |
Committee recommendations
That Council receive this report for information and direct staff to:
1. Continue monitoring at the Robert O. Pickard Environmental Centre as outlined in the body of this report; and
2. Update Committee in the event that deviations are noted and make recommendations for further investigation or public consultation, as required.
Recommandations DU Comité
Que le Conseil prenne connaissance du présent
rapport ŕ titre d’information et demande au personnel de :
1.
poursuivre
la surveillance continue au Centre environnemental Robert O. Pickard, tel qu’il
est exposé dans le corps du présent rapport; et
2. tenir au courant le comité si on
observe des déviations et de recommander des recherches supplémentaires ou une
consultation publique, au besoin.
Documentation
1.
Deputy
City Manager’s report, Infrastructure Services and Community Sustainability
dated 11 June 2009 (ACS2009-ICS-WWS-0016).
Report to / Rapport au:
Planning and Environment Committee /
Comité de l'urbanisme et de
l'environnement
and Council / et au Conseil
Submitted by / Soumis par:
Nancy Schepers, Deputy City Manager/
Directrice municipale adjointe
Infrastructure Services and
Community Sustainability/
Services d’infrastructure et
Viabilité des collectivités
|
City-Wide / Ŕ l’échelle de la Ville |
|
Ref N°: ACS2009-ICS-WWS-0016 |
SUBJECT: Environmental
effects monitoring of the robert O. pickard environmental centre
OBJET: Étude de suivi dES effets sur l’environnement
dU centre environnemental Robert O. pickard
That the Planning and Environment Committee and Council receive this report for information and direct staff to:
1. Continue monitoring at the Robert O. Pickard Environmental Centre as outlined in the body of this report; and
2. Update Committee in the event that deviations are noted and make recommendations for further investigation or public consultation, as required.
Que le Comité de l’urbanisme et de l’environnement et le Conseil
prennent connaissance du présent rapport ŕ titre d’information et demandent au
personnel :
1.
de
poursuivre la surveillance continue au Centre environnemental Robert O.
Pickard, tel qu’il est exposé dans le corps du présent rapport; et
2. de tenir au courant le comité si on
observe des déviations et de recommander des recherches supplémentaires ou une
consultation publique, au besoin.
The
management of potential environmental impacts to the receiving environment has
always figured prominently in the City’s Environmental Strategy. As early as 1998, the City proactively
undertook a variety of field and laboratory studies to determine the effects of
effluent from the Robert O. Pickard Environmental Centre (Pickard Centre) on
the receiving environment of the Ottawa River.
Studies also took place at the Lemieux Island and Britannia Water
Purification Plants during the same time period. Their findings ultimately resulted in the diversion of the
discharge of backwash from those facilities from the Ottawa River, to the
sewage works for treatment at the Pickard Centre.
Environmental Effects Monitoring (EEM) is an integrated approach to environmental management, which attempts to identify any effects or changes in the environment, based on weight of evidence. Effects that are assessed include changes in populations, diversity, health and habitat (including plant growth) of fish, and other organisms living in the river. The weight of evidence approach relies upon a comparison of locations exposed to discharges to a location free of the exposures but otherwise similar in characteristics, to identify environmental effects. Should any environmental effects be identified, work then focuses on determining the cause of the effect(s). For the purposes of EEM, an effect is considered ecologically significant if it impacts on the sustainable use of the fisheries resource.
The
Ministry of the Environment establishes the effluent criteria for wastewater
treatment facilities through Certificates of Approval (C of A). It is important to note that the Pickard
Centre is currently operating in full compliance with its C of A, which
identifies four compliance limits: carbonaceous biochemical oxygen demand
(CBOD), suspended solids, total phosphorous, and E.coli. The Pickard Centre C of A does not address
parameters that are known to be toxic to fish, such as un-ionized ammonia and
chlorine some of which are the subject of federal reporting under NPRI,
National Pollutant Report Inventory.
While historically applied to the pulp and paper industry, the issues
addressed by EEM are beyond the scope of the current basis for approvals as
issued by the Ontario Ministry of the Environment. It is for this reason that EEM reporting is considered
progressive in nature, given its holistic approach.
The first step in the EEM process yielded extremely positive results. Fish communities within the environment of the effluent discharge were as diverse as elsewhere in the river, and in good health. Additional assessments to date have determined and confirmed that:
Benthic invertebrates are spineless creatures that are visible to the naked eye and inhabit the bottoms of water bodies. The growth of certain species that are sensitive to pollution has been inhibited in the discharge plume, and fingernail clams were missing entirely in the affected area for three of the four years of the study. This effect is localized to within 1.8km downstream of the Pickard Centre’s discharge. The cause is unknown, based on measured concentrations of substances in water and sediments, and published tolerances of fingernail clams to chlorine and ammonia. The mode of action is not one of endocrine disruption.
The integrated nature of EEM reporting can result in different interpretations and perspectives. Benthic community changes are typically considered an early warning of the potential effect to fish, but effects on fish have not been observed, and are unlikely to occur as long as effluent quality remains high. A modest but short-term recovery of fingernail clams in 2006 also indicates that recovery in the zone of influence would be very rapid if the causative agent can be identified and managed. In light of this, and the fact that the size of the affected area has not increased over the years, the ecological relevance of this impact is considered to be relatively minor.
It should be noted that the lack of clams below the Pickard Centre discharge is not unusual. Field programs conducted in other areas downstream of treated municipal wastewater effluents have produced similar results. Although their absence is a concern, indications are that these conditions are acceptable, provided they remain stable over time, both in magnitude and geographic extent. Continued monitoring will occur to ensure that this remains to be the case, and to verify that the quality of waters and sediments in the receiving area do not deteriorate. Studies to determine the specific cause of observed effects will also be continued. Any additional observed changes in the receiving environment will be communicated to the public.
RÉSUMÉ
La gestion des effets
possibles sur l’environnement dans le milieu récepteur a toujours occupé une
place de premier plan dans la Stratégie environnementale de la Ville. Dčs 1998, la Ville a entrepris de maničre
proactive une série d’études sur le terrain et en laboratoire visant ŕ
déterminer les effets des effluents du Centre environnemental Robert O. Pickard
(Centre Pickard) sur le milieu récepteur de la rivičre des Outaouais. Des études ont également eu lieu aux usines
de purification de l’eau de l’île Lemieux et de Britannia pendant la męme
période. Leurs résultats ont abouti ŕ
la déviation des rejets de lavage ŕ contre-courant de ces usines de la rivičre
des Outaouais, vers les stations d’épuration pour ętre traitées au Centre
Pickard.
L’étude de suivi des effets sur l’environnement
(ESEE) est une approche intégrée de gestion environnementale qui s’efforce de
cerner les effets ou changements survenus dans le milieu, d’aprčs la valeur
probante des données disponibles. Les
effets évalués comprennent les changements dans les populations, la
biodiversité, la santé et l’habitat (y compris la croissance des plantes) du
poisson et d’autres organismes vivant dans la rivičre. L’approche de la valeur probante se fonde
sur une comparaison entre les sites exposés aux décharges et un site similaire
par ses caractéristiques, mais exempt d’exposition, pour mesurer les effets sur
l’environnement. Si on établit un effet
sur l’environnement, on se concentre alors sur la détermination de la cause du
ou des effet(s). Aux fins de l’ESEE, un
effet est considéré comme significatif sur le plan écologique s’il a une
incidence sur l’utilisation durable de la ressource pour la pęche.
C’est le ministčre de l’Environnement qui établit les
critčres concernant les effluents pour les installations d’épuration de l’eau
usée au moyen de certificats d’autorisation.
Il importe de noter que le Centre Pickard fonctionne actuellement de
maničre entičrement conforme ŕ son certificat, qui fixe quatre seuils de conformité : demande biochimique en oxygčne des matičres
carbonées, solides en suspension, phosphore total et E. coli. Le certificat
d’autorisation du Centre Pickard n’aborde pas les paramčtres reconnus comme
toxiques pour le poisson, comme l’ammoniaque et le chlore non ionisés, qui font
l’objet, pour certains d’entre eux, de rapports fédéraux en vertu de
l’Inventaire national des rejets de polluants (INRP). Bien qu’elles
s’appliquent traditionnellement ŕ l’industrie des pâtes et papiers, les
questions abordées par l’ESEE vont au-delŕ de la portée courante des
autorisations délivrées par le ministčre de l’Environnement de l’Ontario. C’est pourquoi les rapports d’ESEE sont
considérés comme progressifs, étant donné leur approche holistique.
La premičre étape du processus d’ESEE a donné
des résultats extręmement positifs. Les
communautés de poisson dans l’environnement du rejet d’effluents étaient aussi
diverses qu’ailleurs dans la rivičre, et en bonne santé. Les évaluations additionnelles effectuées
jusqu’ici ont déterminé et confirmé les points suivants :
Les invertébrés benthiques sont des
organismes invertébrés visibles ŕ l’śil nu et habitant le fonds des cours
d’eau. La croissance de certaines
espčces sensibles ŕ la pollution a été freinée dans le panache de décharge, et
les sphćriinés avaient disparu du
secteur touché pour trois des quatre années de l’étude. Cet effet se situe ŕ moins de 1,8 kilomčtre
en aval de la décharge du Centre Pickard.
La cause est inconnue, d’aprčs les concentrations mesurées des
substances dans l’eau et les sédiments, et les tolérances publiées des
sphćriinés au chlore et ŕ l’ammoniaque. Le mode d’action n’est pas la
perturbation endocrinienne.
La nature intégrée des rapports
d’ESEE peut conduire ŕ diverses interprétations et perspectives. L’évolution au sein de la communauté
benthique est habituellement considérée comme une alerte préalable ŕ une
incidence potentielle sur le poisson, mais on n’a pas observé de telles incidences,
qui sont peu probables tant que la qualité des effluents demeure élevée. Un rétablissement modeste, mais ŕ court
terme des sphćriinés en 2006 indique également que le rétablissement dans la
zone d’influence serait trčs rapide si l’agent responsable peut ętre établi et
maîtrisé. Dans ce contexte et comme le
secteur touché ne s’est pas étendu au cours des années, la pertinence
écologique de cet impact est considérée comme relativement mineure.
Il convient de noter
que l’absence de sphćriinés sous la décharge du Centre Pickard n’est pas inhabituelle. Des projets sur le terrain réalisés dans
d’autres secteurs en aval des effluents municipaux d’eaux usées traitées ont
donné des résultats similaires. Bien
que leur absence soit préoccupante, tout indique que ces conditions sont
acceptables, si elles demeurent stables avec le temps, pour ce qui est de leur
importance comme de la surface géographique.
L’étude de suivi se poursuivra afin de s’assurer que cela reste le cas,
et que la qualité des eaux et des sédiments dans le milieu récepteur ne se détériore
pas. Des études visant ŕ déterminer la
cause précise des effets observés se poursuivront également. Tout autre changement observé dans le milieu
récepteur sera communiqué ŕ la population.
BACKGROUND
The management of potential environmental impacts to
the receiving environment has always figured prominently in the City’s
Environmental Strategy. As early as
1998, the City proactively undertook a variety of field and laboratory studies
to determine the effects of effluent from the Robert O. Pickard Environmental
Centre (Pickard Centre) on the receiving environment of the Ottawa River. Studies also took place at the Lemieux
Island and Britannia Water Purification Plants during the same time period. Their findings ultimately resulted in the
diversion of the discharge of backwash from those facilities from the Ottawa
River, to the sewage works for treatment at the Pickard Centre.
More recent studies have been undertaken in response
to Environment Canada’s requirement for the development and implementation of a
Pollution Prevention Plan for the Pickard Centre. These works have also been
identified as water quality initiatives currently underway to protect the
Ottawa River in previous reports,
ACS2008-PWS-WWS-0017 – Water Quality Modeling of the Ottawa River, and
ACS2008-ICS-WWS-0021 – Ottawa River Water Quality Assessment Interim
Report.
This report serves to update Council on the results
of the studies to date, make recommendation for future monitoring and identify
potential requirements for public consultation.
DISCUSSION
The City of Ottawa, through the Environmental
Strategy, commits to demonstrate and promote leadership in environmental
stewardship and to take an ecosystem approach to the protection of aquatic
systems. It also recognizes the need to reduce the City’s global environmental
impact. Recently, the Planning and
Environment Committee established strategic priorities and opportunities
through its 2009-2010 Strategic Planning Session. Environmental Effects Monitoring (EEM) is an important tool in
this regard, given that it measures the impact of discharges from municipal
facilities on the aquatic environment, and enables the long-term assessment of
initiatives to improve water quality.
Its implementation is a result of the recognition of the importance of
the Ottawa River, and the need to provide long-term protection of the City’s
watersheds. Reporting of results will
work towards the building of community trust and confidence.
EEM is an integrated approach to environmental management, which attempts to identify any effects or changes in the environment, based on weight of evidence. Effects that are assessed include changes in populations, diversity, health and habitat (including plant growth) of fish, and other organisms living in the river. The weight of evidence approach relies upon a comparison of locations exposed to discharges to a location free of the exposures but otherwise similar in characteristics, to identify environmental effects. Should any environmental effects be identified, work then focuses on determining the cause of the effect(s). For the purposes of EEM, an effect is considered ecologically significant if it impacts on the sustainable use of the fisheries resource.
The goals of EEM are to:
·
Document and confirm
the presence of any effects;
·
Determine the
magnitude and extent of any negative effects;
·
Investigate the cause
of said effects; and
·
Implement mitigation
measures towards their reduction or elimination.
This
approach was first implemented by Environment Canada for the pulp and paper
industry in 1992 as part of that industry’s compliance with the terms and
conditions of the Fisheries Act.
The methodology has since been applied to the mining industry. The City of Ottawa is the first municipality
to voluntarily apply the EEM technique to its own facilities. A description of terms is included in
Appendix 1.
The
Ministry of the Environment establishes the effluent criteria for wastewater
treatment facilities through Certificates of Approval (C of A). It is important to note that the Pickard
Centre is currently operated in full compliance with its C of A, which
identifies four compliance limits:
carbonaceous biochemical oxygen demand (CBOD), suspended solids, total
phosphorous and E.coli. The assumption
being that a secondary treatment facility operated in compliance with these
criteria, will obtain the contaminant reduction or elimination consistent with
this level of treatment. The Pickard
Centre C of A does not have specific effluent criteria for either un-ionized
ammonia or chlorine, which are parameters known to be toxic to fish. The issues addressed by this study are
beyond the scope of the current basis for approvals as issued by the Ontario
Ministry of the Environment. It is for
this reason that EEM reporting is considered progressive in nature, given its
holistic approach.
The Pickard Centre is required by Environment Canada to have a Pollution Prevention Plan for a number of parameters. EEM is a component of this Plan, and the plant effluent, river and sediments are monitored for the parameters of concern. EEM will also assist with the site-specific risk assessments that will be required in future as part of a Canada-wide Strategy for the Management of Municipal Wastewater Effluent, that was recently endorsed by the Councils of Ministers of the Environment.
An external review of the wastewater processes at the Pickard Centre identified chlorine, un-ionized ammonia and phosphorous as parameters of particular concern in the continuous discharge to the Ottawa River.
The City of Ottawa undertook a variety of field and laboratory studies to determine the effects of effluent from the Pickard Centre on the receiving environment of the Ottawa River, including fish and benthic invertebrates. Studies have been designed, specifically to determine if effects can be linked to chlorinated effluent, given that chlorination occurs between May 15 and November 15 each year. Table 1 presents a summary of the assessments completed to date.
Table 1: Study components from
2005 to 2008
Study
Component
|
2005 |
2006 |
2007 |
2008 |
|
Water Chemistry (Ottawa River) |
|
X |
X |
X |
|
Water Chemistry (Final Effluent) |
|
X |
X |
X |
|
Sediment Chemistry |
|
|
X |
X |
|
Benthos Sampling |
X |
X |
X |
|
|
Caged Bivalve |
|
X |
X |
X |
|
Biobasket |
|
|
X |
X |
|
Acute Toxicity (Final Effluent) |
|
|
X |
X |
|
Chronic Toxicity (Ottawa River) |
|
|
X |
X |
|
Final Effluent Bioassay |
|
X |
|
|
|
Sediment Bioassay |
|
|
X |
|
|
Pickard Centre Plume Model |
|
X |
|
|
|
Sediment Transport Analysis |
|
X |
|
|
|
Fish Community |
X |
X |
|
|
The Environment Canada approach to the evaluation of biological impacts of municipal wastewaters (Kilgour et al., 2005) recommends reconnaissance level inventories of fish communities as a first step. Surveys in the area of the Pickard Centre discharge and at a reference site upstream were conducted in 2005 and 2006.
This first step in the EEM process yielded extremely positive results. Fish communities within the nearfield environment of the effluent discharge were as diverse as elsewhere in the river, and included lake sturgeon, yellow perch, brown bullhead, northern pike, bass (smallmouth and largemouth), walleye, white sucker, and a variety of smaller species. Yellow perch in the exposure area were also in good health, based on condition factor, liver size and gonad size, and compared to populations known to be healthy. The fisheries data in aggregate, therefore, indicated no undue impacts.
Benthic invertebrates are animals without a spine, visible to the naked eye, that inhabit the bottoms of aquatic systems. They have varying degrees of sensitivity to pollution and are exposed directly to the conditions in the environment. As a result, their presence or absence serves as useful indicators for assessing the waterbody’s health. Initial sampling of benthic invertebrates for this study occurred in the fall of 2005. The community in the reference area upstream of the Pickard Centre was found to be relatively typical of what is found in large sand-bottomed rivers. Conditions in the exposure area indicated a reduction in diversity, including the absence of fingernail clams.
A second field program was carried out in 2006 to confirm these effects. Benthic sampling in May indicated that fingernail clams remained generally absent, or at least in very low numbers within the exposure area. However, by October a modest recovery of fingernail clams was observed. They were present at all of the exposure areas sampled, with the greatest abundance in the area closest to the discharge pipe. Results of a twenty-five day study where caged clams were placed directly in the exposure zone, and two short-term studies to assess whether or not the clams could survive in river sediments and final effluent, also indicated no acute mortality.
The inconclusive nature of the results from these studies justified continued monitoring to determine why fingernail clams were absent one year and recovered the next. In 2007 and 2008, longer-term studies were carried out to determine if the final effluent contained substances that were bioavailable and would cause death, changes in growth, or changes in reproductive output. Studies were also designed to assess whether the lack of sensitive benthic species in the exposure area was due to the poor habitat (i.e. coarse sand) and not chemical influences.
These additional studies provide evidence that the Pickard Centre effluent contains substances that negatively impact sensitive benthic species. Data suggests that this effect is localized to within 1.8km of the Pickard Center’s discharge. It should be noted that the lack of clams below the Pickard Centre discharge is not unusual. Field programs conducted in other areas downstream of treated municipal wastewater effluents have produced similar results.
·
Total phosphorous concentrations always exceeded the
Provincial Water Quality Objectives (PWQO).
Phosphorous is
non-toxic to aquatic organisms at levels and forms present in the environment.
Testing of the
final effluent was also undertaken to measure the mortality of fish subjected
to Pickard Centre final effluent over a four-day period. The results of these tests are inconclusive. Due to conditions inherent
to the shipping and regulatory testing procedures, the samples that were tested
in the laboratory were not representative of what was discharged at the end of
pipe at the Pickard Centre. These
procedures have been amended to compensate for these issues. Testing in the summer of 2009 should
provide more conclusive evidence as to whether or not the effluent from the
Pickard Centre contains un-ionized ammonia in concentrations that may create
negative impacts on the fish and benthic communities in the Ottawa River.
Understanding water chemistry is necessary to
determine possible causes of biological impacts to the Ottawa River. Samples of the Ottawa River water were taken
at locations 100m upstream of the Pickard Centre discharge (reference), 250m
downstream (near-field), 500m downstream (mid-field), and 1.8km downstream
(far-field). Each sample was analyzed for fifty-eight parameters.
It is important to note that surface water
quality guidelines are usually based on laboratory studies and designed to
protect the most sensitive Canadian species, under the worst-case
conditions. For example, the guideline
for the protection for aquatic life for chlorine is higher than the lowest
reliable detection limit. Therefore,
any detection of chlorine in the aquatic environment would be considered to be
posing a potential risk to aquatic life.
Guidelines also do not take into account the increased tolerances that
occur naturally.
The results for the sampling that took place in
the Ottawa River upstream and downstream of the Pickard Centre are summarized
as follows:
Testing was also undertaken to determine if the Ottawa River water has a measurable, relatively long-term effect, on standard test organisms. This test was performed over a 7-day period on Ottawa River water samples obtained from the affected zone, approximately 250m downstream of the Pickard Centre diffusers, using fathead minnows and freshwater algae. Results indicate that there is no growth impairment, and the river at this location, is not chronically toxic. The absence of chronic toxicity in these tests can also be used to support a general conclusion that the discharge of effluent to the Ottawa River poses little risk to fish and plants, a finding consistent with field observations.
Effluent discharges can have an impact on the chemical composition of river bottom sediment. Potential contamination of sediment may have a negative impact on benthic macro invertebrates. Initial study results indicating moderate impairment to the benthic community therefore prompted testing of the sediments to determine whether or not this was a potential cause of the effect.
The
sediment analyses that occurred in 2007 indicated that chromium, arsenic,
cadmium and lead were at concentrations below detection limits and well below
Provincial Guidelines for the protection of aquatic organisms. Mercury concentrations were above guidelines
in the reference area and mid- and far-field locations. Additional analyses were conducted in 2008
to provide a more comprehensive assessment.
In 2008, all sample results were below guidelines, and sediment chemistry downstream of the Pickard Centre was generally similar to reference conditions. Mercury was not detected. This assessment indicates that sediments in the river below the Pickard Centre discharge are unlikely to pose a risk to aquatic life; and that the wastewater treatment plant effluent appears to have little to no impact on the sediment chemistry.
Results of the EEM studies to date are as follows:
· With very few exceptions, the quality of the Ottawa River downstream of the Pickard Centre is generally within guidelines or below detection in all locations;
· The outcome of chronic toxicity testing supports a general conclusion that the discharge of effluent to the Ottawa River poses little risk to fish and plants;
· The fish community in the zone of impact is diverse and healthy, indicating no observed effects;
· There is little to no impact on the sediment chemistry;
· The growth of certain species of pollution-sensitive benthic invertebrates has been inhibited, including the complete absence of fingernail clams, in a zone 1.8km downstream of the Pickard Centre discharge;
· Concentrations of chlorine and un-ionized ammonia in the Ottawa River downstream of the Pickard Centre exceed Federal Guidelines for the Protection of Aquatic life; however, the concentrations in the river have been below concentrations shown in scientific studies to pose risks to fingernail clams; and
· Concentrations of total phosphorous in the Ottawa River downstream of the Pickard Centre exceed Provincial Water Quality Objectives. Phosphorous is non-toxic to aquatic organisms at levels and forms present in the environment.
· A comparison of scientific studies regarding the concentrations of un-ionized ammonia and chlorine that would pose risk to clams, and the water and sediment chemistry data collected as part of this study, does not substantiate that either substance is the cause of the relatively minor inhibitory effect on their growth downstream of the Pickard Centre. Studies also indicate that the mode of action is not one of endocrine disruption. As a result, the cause of the benthic inhibition is currently unknown.
Fingernail clams are dominant (numerically) in the benthos of the Ottawa River, and are very diverse in this region. In shallow waters they are eaten by ducks; in deeper waters consumed by bottom-feeding fishes. An absence of clams within the zone of influence is unlikely, by itself, to cause a cascade of ecological impacts.
The ecological relevance of their absence downstream of the Pickard Centre discharge is considered to be relatively minor. Although it is unfortunate that they are absent, it is believed that the zone of influence is somewhat limited, being within 1.8 km of the outfall diffuser. There is, further, no reason to believe (based on the data that have been acquired over the past four years) that the zone of impact is getting or should get larger over time. As defined by Kilgour et al. (2005) an effect that does not get any larger over time should be considered a “warning” level effect, not “severe” justifying continued monitoring to make sure effects do not get any larger. Further, these various studies demonstrated a modest but short-term recovery in 2006. That finding indicates that recovery in the zone of influence would be very rapid if the causative agent can be identified and managed.
Additional support for the
conclusion that the biological effects of the Pickard Centre discharge are of
minor concern is related to the absence of apparent impacts to the local
fishery. Studies documented a diverse
assemblage of fish (including lake sturgeon and walleye) using the middle of
the river within the nearfield mixing zone.
Analysis of indices of growth and condition of yellow perch from the
farfield exposure areas also provided no indication of undue stress. Finally, there have been no reports of fish
kills, or other signs of undue impact in the local or regional area. There is thus no evidence for impacts to the
fish community of a nature that would be considered severe or unacceptable
(Kilgour et al. 2005).
Concentrations of chlorine and un-ionized ammonia in the Ottawa River downstream of the Pickard Centre exceed Federal Guidelines for the Protection of Aquatic Life; however, the concentrations in the river have been below concentrations shown in scientific studies to pose risks to fingernail clams. As a result, the cause of the benthic inhibition is currently unknown.
Concentrations
of total phosphorous in
the river downstream of the Pickard Centre exceeds PWQO. This guideline was established to prevent
excessive plant growth in water bodies.
Underwater observations in the Ottawa River have shown little plant
growth on the river bottom in the vicinity of the Pickard Centre discharge,
indicating that the elevated total phosphorous concentrations are not having a
detectable impact on the immediate receiving environment. As a result, enhanced phosphorous removal is
not recommended at this time.
Continued monitoring of the benthic community after dechlorination of the final effluent is implemented will shed light on whether chlorine is the substance creating the impact, or whether other enhanced wastewater treatment methodologies should be considered for the Pickard Centre.
Next Steps
§ Some key follow-up studies can be recommended.
REFERENCES
Environment Canada. 2005. Metal mining guidance document for aquatic environmental effects monitoring.
Kilgour, B.W., K.R. Munkittrick, C.B. Portt, K.
Hedley, J. Culp, S. Dixit, G. Pastershank.
2005. Biological criteria for municipal
wastewater effluent monitoring programs. Water Quality Research Journal of
Canada, 40:374-387.
ENVIRONMENTAL IMPLICATIONS
Improving the quality of the effluent that is
discharged to the Ottawa River will assist in fulfilling the goals of the Ottawa
20/20 and the City’s Environmental Strategy.
It also serves to demonstrate the City’s leadership in water environment
protection and fulfills the strategic direction provided by Planning and
Environment Committee.
No consultation has occurred to date. It is expected that consultation regarding
enhanced wastewater treatment options will be integrated within the four
workshops regarding the draft Integrated Protection Strategy for the Ottawa
River, that are scheduled to take place during the third quarter of 2009.
LEGAL/RISK MANAGEMENT
IMPLICATIONS
There are no direct legal or risk management implications arising from the recommendations or actions in this report. Documentation of the EEM process and findings is a good risk management practice.
This report has not financial implications. However, initiatives to reduce the Pickard
Center’s impact on the Ottawa River will impact the Long Range Financial Plan
and Corporate Departmental Plans.
Preliminary capital and operating costs have been identified as part of
the Ottawa River Water Quality Assessment Interim Report - ACS2008-ICS-WWS-0021.
Document 1 – Description of Terms
The Water Environment Protection Program will
continue to work in cooperation with Wastewater and Drainage Services towards
the successful implementation of their Pollution Prevention Plan and will
continue to monitor the receiving environment, as long as effects are present. Component studies to determine the specific
cause of observed effects will be continued and public consultation undertaken,
if necessary, to determine the concern related to observed effects if such
effects increase over time. Mitigative
technologies will be implemented wherever effects are considered undue or
severe.
Document 1
Description of Terms
Study Component
|
Description |
|
Acute Toxicity
Testing |
·
Measured the mortality of test organisms (rainbow trout and Daphnia
magna) subjected to Pickard Centre final effluent over a four-day
period. |
|
Benthos
Sampling |
·
Samples of sediment were taken from various places in the River and
the organisms found living in each sample were preserved, counted and
identified. Statistical analyses of
the populations enabled the determination of whether or not the effluent was
having an impact. |
|
Biobasket Study |
·
Rock filled baskets were deployed at various locations in the River,
to provide a favourable habitat for pollution sensitive benthic species which
typically do not colonize coarse, abrasive sand as is found in the study
area. This enabled further assessment
of whether the impacts were related to chemical substances or unsuitable
habitat in the area. |
|
Caged Bivalve
Study |
·
“Cages” containing known numbers of clams were deployed at various
locations in the River and left for periods of different duration and then
removed and the populations assessed for growth and mortality. This enabled the determination of whether
or not the effluent displayed any toxic effects to the clams, and if so, the
geographical extent of those effects.
|
|
Chronic
Toxicity Testing |
·
Measured the growth of test organisms (fathead minnows and freshwater
algae) subjected to samples collected from the Ottawa River, to determine if
there is as a measurable, but not lethal, effect, over a relatively long
period of time (7 days). |
|
Endocrine
Disruptor |
·
Compound that acts like a hormone, disrupting the physiologic
function of animals, potentially resulting in adverse effects. |
|
Final Effluent
Bioassay |
·
Known numbers of clams were placed in samples of chlorinated final
effluent and observed for a three-day period to determine whether or not the
final effluent contained substances that were bioavailable and toxic. |
|
Fish Community
Survey |
·
Determined the population of the fish community with respect to
numbers, diversity and health, in the affected area. |
|
Pickard Centre
Plume Model |
·
Conductivity sampling in the
river, and computer modeling was used to predict the dispersion of the
Pickard Centre final effluent. |
|
Sediment
Bioassay |
·
Known numbers of clams were placed in sediment samples collected from
various locations in the river and observed for an eight-day period to
determine whether or not the sediments contained substances that were
bioavailable and toxic. |
|
Sediment
Chemistry |
·
Samples of the sediment on the river bottom are taken to assess their
chemical characteristics to determine whether any contamination has occurred,
and if so, to what extent. |
|
Sediment
Transport Analysis |
·
The rate at which sediments move in the river bottom as a result of
high flows, such as those experienced during spring freshet, was calculated
to determine if this impacted the presence or absence of benthic organisms
downstream of the Pickard Centre discharge. |
|
Water Chemistry
– Ottawa River and Final Effluent |
·
Samples are taken to assess the chemical characteristics of the
Ottawa River and Pickard Centre final effluent, and data are compared against
Provincial and Federal Objectives and Guidelines where possible. |