Research, Monitoring and Environmental Protections on the Shubenacadie River Estuary. June 2017 (updated September 2017)

Transcription

1 Research, Monitoring and Environmental Protections on the Shubenacadie River Estuary June 2017 (updated September 2017) 1

2 Overview 1. What is the Alton Natural Gas Project? 2. Summary of River Research and Studies 3. Summary of River Monitoring 4. Dalhousie University Research & Monitoring Mapping extensive activity Striped bass research Highlights of findings Fish species profiles Water quality sampling Salinity tolerance of Striped bass 5. Ikanawtiket River Study 6. Infrastructure Reduces Impacts 7. Brine Release 8. Summary of Fish Protection Measures 2

3 What is the Alton Natural Gas Project? To provide clean, affordable and reliable natural gas for Nova Scotia, we are developing an underground natural gas storage facility. Natural gas will be stored safely deep underground in salt caverns. To make the caverns, the salt will be gradually dissolved using tidal water from the Shubenacadie River estuary in a process called brining. The brine created by this process, a mixture of tidal water and dissolved salt, will be released slowly within the range of normal salinity for the Shubenacadie River estuary. 3

4 What is the Alton Natural Gas Project? Brining process Storage process 4

5 Summary of River Research and Monitoring , preliminary independent by Jacques Whitford, Martec, Matrix, Soltech, Thaumas and Department of Fisheries and Oceans (DFO), provincial Environment assessment documents present, Dalhousie University researchers conduct most comprehensive biological study ever conducted on Shubenacadie River estuary including: Hydrodynamics of the river Measure salinity Inventory fish species present Examine the wider food web present, monthly estuary water quality sampling present, Dalhousie laboratory salinity tolerance tests on young Striped bass. Ikanawtiket water quality study of creeks and streams flowing into the Shubenacadie. 5

6 Summary of River Documents and Approvals 2014 detailed monitoring plan for operations was approved by DFO and Environmental Canada Mi kmaq of Nova Scotia /Conestoga Rovers review of the Project Improves monitoring plan Includes a 44 species review with detailed assessment of swimming ability and salinity tolerance for 20 different fish Fish Fact Sheets 2016 Nova Scotia Environment Industrial Approval permit which included the final monitoring plan and reporting requirements. 6

7 Dalhousie Research & Monitoring, Present River data collection includes: Identifying what species are present (time of year, in what numbers) The salinity, depth and temperature of the water Water quality River velocity To date, over 5,000 hours on the river collecting data. In the lab, data is analysed and comparisons are made between years and among species. To date, more than 12,000 hours in the lab counting and analysing the data. 7

8 Dalhousie Research & Monitoring - Mapping Extensive Activity Starting in 2008, ongoing assessment monitoring. Species monitoring from the river mouth to the salt front, upriver from Alton and about ~ 35 to 40km upriver from the mouth. Salinity monitoring along 32km on the Shubenacadie River estuary and 9km of the Stewiacke River. Also includes: loggers measure depth and temperature beach seine netting plankton net tows 8

9 Dalhousie Research & Monitoring - Mapping Activity in Cobequid Bay Species monitoring along the shore in five locations from Parrsborro to Little Dyke - with DFO. Plankton net monitoring 18km out into Cobequid Bay. 9

10 Dalhousie Research & Monitoring, Present Research Focus Early life stage Striped bass (eggs, larvae and juveniles). Striped bass are the only fish species with early stages present at the Alton site But all species caught are documented. Nearly a decade of detailed data on young fish from more than 20 species; see the Fish Fact Sheets. 10

11 Dalhousie Research & Monitoring - Striped Bass Research Areas Timing of spawning Number of eggs per female Abundance of eggs, larvae and juveniles Distribution and location Stomach content Number of prey and location Growth rates 11

12 Dalhousie Research & Monitoring to Present, Striped Bass Research Timing of spawning; from mid-may to mid-june Figure 1. Timing of Striped Bass spawning over ten years indicated by daily mean egg density in the Shubenacadie River estuary. Each coordinate is a mean of between 3 and 10 plankton net tows in the main channel on either the ebb or flood tide ( no eggs; ; 11-99; ; >1000 eggs/m 3 ). 12

13 Dalhousie Research & Monitoring to Present, Striped Bass Research Environmental factors strongly influence the survival of Striped bass eggs, larvae and juveniles, primarily: Rainfall Water temperature Wind and tides Factors influencing fish growth: Timing of spawning Food/prey availability Water temperature 13

14 Dalhousie Research & Monitoring - 20 Species Profiles Alton Safeguards and Mitigation Measures 44 species were identified as culturally important or as indicators of ecosystem health in and around the Alton river site. These species were screened for potential effects from the project. The 20 most sensitive species were profiled in Fish Fact Sheets. For each species the information covered includes: Biology and life cycle Habitat Alton Gas survey results, Implications of the Alton Gas Natural Storage project Life stage salinity tolerances 14

15 Dalhousie Research & Monitoring - Salinity Tolerance of Striped Bass Started testing in Fish (2.5-12cm) were exposed for one hour to six variable salinity levels (between 10 and 100 parts per thousand of salt, or ppt), then maintained at 2ppt for 96 hours. Ocean salinity coastal NS ~30ppt and freshwater 0ppt. During 2017, eggs, larvae and juveniles will be tested. 15

16 Research & Monitoring - Water Quality Sampling Monthly Samples Three years of monthly samples, (except when river was iced over). Measured 58 parameters including chloride, fluoride, sulphate, turbidity and nitrates. Highlights Large variations between low and high tide; size of the tide and the volume of fresh water runoff greatly influence water quality. Shubenacadie River estuary water naturally exceeds water quality standards for eleven metals at some stages of the tide (aluminum, arsenic, cadmium, copper, iron, lead, manganese, nickel, selenium, strontium and zinc.) 16

17 IKANAWTIKET River Study The study aims to identify all tributaries flowing into the Shubenacadie River from the mouth of the Cobequid Bay to the confluence with the Stewiacke River (~30km). The objective of the study is to develop a water quality baseline and identify potential impacts from surrounding land use practices. Water quality sampling is being conducted on site to measure dissolved oxygen (DO), ph, salinity, conductivity, temperature, stream velocity and depth. Water samples are also analyzed for fecal coliforms, E.coli, nitrates/nitrites, total organic carbon, and heavy metals. Mud samples are collected and analyzed for biological species composition and abundance. 17

18 IKANAWTIKET River Study Over 50 tributaries were identified on topographic maps, but some later determined to be agricultural irrigation or seasonal streams. In total, 24 tributaries were sampled in Development of the water quality baseline continued with these 24 sites resampled in Collecting a water sample at Rines Creek in

19 Alton Infrastructure Reduces Impacts

20 Alton Infrastructure Reduces Impacts - Design Alton s tidal water intake significantly surpasses DFO standards for fish protection. Alton has constructed a side channel with various features for reducing impacts Water is screened through a thick rock wall called a gabion wall. Projection of the wall into the channel and its alignment into the channel ensures water flows fast and smooth. The velocity of the water along the gabion wall will be times faster than the velocity of the flow into the gabion wall; the difference in speed stops aquatic life from being drawn into the water intake. The release occurs through two perforated pipes paired with aeration tubes to ensure mixing. Gabion wall during construction 20

21 Brine Release: Salinity in the Alton Channel The Shubenacadie River estuary naturally experiences a range of salt concentrations with the tide. Salinity in the estuary is influenced by fresh water run off from rainfall. Organisms in a tidal river are accustomed to range and changes in salt levels. Brine release takes place in the constructed channel alongside the river. Channel salinity will mirror the river s natural salinity. 21

22 Brine Release: Monitoring for Salinity plus Water Sampling 22

23 Brine Release: Conditions of the Approved Monitoring Plan Salinity checks along 32km on the Shubenacadie River. Salinity checks along 9 km of the Stewiacke River. Species monitoring from the Alton site to the salt front on the Shubenacadie River, about 35 to 40km upriver from the river mouth. 23

24 Summary of Fish Protection Measures Numerous studies provided the framework. Constant, real-time salinity monitoring takes place in the Alton channel, as well as up and down river. Brine release schedule is based on the river velocity and natural background salinity in the estuary to minimize any ecosystem impact. Water intake through a gabion wall to minimize the chance of drawing in small organisms. An observation well is located within the water intake; organisms will be detected if drawn in. 24

25 Summary of Fish Protection Measures Sampling at the water intake and brine discharge site for the presence of any species, their numbers and life stage. Refrain from brining for 24 days in springtime during Striped bass spawning season. Acoustic tagging of Atlantic salmon smolt and adult Striped bass to monitor their use of the constructed channel. 25

26 Questions For more information on Alton, visit Questions? 26