PEI Water. A Water Act Backgrounder September Water Act Consultation

Transcription

1 PEI Water A Water Act Backgrunder September 2015 Water Act Cnsultatin Fal

2 Outline Water in ur lives The amunt f water and hw we use it Prtecting the envirnment Water quality Water management Water Act Cnsultatin Fall

3 Water in ur lives We need it fr life It helps supprt ur ecnmy and we value it fr many ther reasns as well Recreatin Wildlife habitat

4 Water Cycle PEI Average Annual Amunts Evaptranspiratin 440 mm Precipitatin 1100 mm Surface Run Off 260 mm Grundwater 400 mm Fall

5 Water Quantity Fter Text 9/25/2015 5

6 Grundwater in PEI Generus, stable, predictable amunts virtually anywhere due t high recharge rate thrugh the thick sandstne bedrck Susceptible t cntaminants. Sle surce f drinking water Supplies mst f the water fr industrial, cmmercial and agricultural uses. Annual grundwater recharge stacked n a sccer field wuld be 300 km high Annual grundwater usage stacked n a sccer field wuld be 4 km high A prtin f pumped grundwater is returned t the aquifer Fresh Grundwater Usage Residential 52% Industrial/Cmmercial 30% Livestck 6% Irrigatin 2% Gethermal 11% Image: curtesy USGS 6

7 Hw wells wrk Grundwater ccupies pre spaces in ur sandstne bedrck It flws frm higher elevatins t lwer elevatins Wells divert sme grundwater frm it s natural flw path Water Table Nnpumping well Pumping well Cne f depressin Well depth m Grundwater flw paths Grundwater discharge t stream (base-flw) m

8 Water Table Hw wells wrk Lwer water table arund a pumping well (cne f depressin) can affect the level in near by wells The cne f depressin size varies with pumping rate, usually a distance f m frm a high capacity well Nnpumping well Pumping well Cne f depressin grund surface Well depth m "drawdwn" in pumping well m m pumping water level "interference" in nnpumping well static water level Grundwater flw paths Grundwater discharge t stream (base-flw) m

9 Water Table Hw wells wrk Lwer water table arund a pumping well (cne f depressin) can affect the level in near by wells The cne f depressin size varies with pumping rate, usually a distance f m frm a high capacity well Nnpumping well Pumping well Cne f depressin Well depth m BB Grundwater A small lwering discharge f the water t stream (base-flw) Grundwater flw table paths can result in a large impact n streams m

10 High capacity wells n PEI Prduce mre than 50 gallns /min require a permit >200 high capacity wells (~20,000 private wells are lw capacity n permit required) Lcal water stress in sme watersheds frm high municipal and industrial water usage High Capacity Wells Number f High Capacity Wells Central Supply Industrial/ Cmmercial Irrigatin (Agr) Irrigatin (Glf) Aquaculture Other (Fire, Gethermal) Fall

11 Lng Term Grundwater Levels Essentially flat with seasnal fluctuatins Dry cnditins quickly fllwed by return t nrmal cnditins Nte the dry cnditins in late 2001 and early Water Act Cnsultatin Fall

12 Where Grundwater Flws Precipitatin Watershed Bundary Surface Run Off Perclatin Grundwater Grundwater Divide Water Act Cnsultatin Fall

13 Height abve sea level (m) Flw (m 3 /s) Strng Cnnectin Between Grundwater and Surface Water Grundwater discharge (base flw) frms ~60% f average annual stream flw Mst f grundwater flw ccurs in the shallw part f the aquifer Stream Flw and Base Flw at West River Base Flw Stream Flw Grundwater levels: High spring due t melting f accumulated snw, precipitatin and lw evaptranspiratin 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nv Dec Grundwater Table at Sleepy Hllw Lw - late summer due t high evaptranspiratin 6 5 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nv Dec Water Act Cnsultatins Fall

14 Seasnal Headwater Streams Parts f headwater streams dry up naturally Due t seasnal variatin f grundwater table Range frm tens t hundreds meters Dry sectin culd be even lnger in sme dry years High grundwater extractin culd lengthen the dry area in summer and early fall. 1 km Dry Stream Area Water Act Cnsultatin Fall

15 Headwater Streams (natural variatin) Natural Seasnal Headwater Streams j i h g f e d c b a Nt measured in Spring Fall Dry Stream Length (m) Observatins by the Kensingtn Nrth Watershed Assciatin Water Act Cnsultatins Fall

16 Impacted Site Winter River Headwater High extractin rate Increases natural drying up f headwater in Brackley area Ttal length f dry area >2 km Actual distance f additinal amunt frm pumping cannt be easily determined as pumping has been ging n since the 1930s Well fields established befre water was regulated Current extractin at the Brackley and Unin well fields is higher than that allwed under the water extractin plicy established in 2010 City f Charlttetwn is required t create a new pumping rate plan Winter River Watershed Hardy's Pnd Brackley Unin Charlttetwn Sufflk kilmetres Water Act Cnsultatins Fall

17 Water Quality Water Act Cnsultatin Fall

18 Where Water Gets Its Characteristics Characteristics depends n what materials it cmes in cntact with, bth natural and man-made Rain water is slightly acidic Run-ff frm rainfall washes materials such as sil, bacteria and ther cntaminants frm the land surface directly int streams Perclating water disslves sme f the minerals in the sil. Elements like calcium and magnesium (which make water hard ) enter grundwater Man-made cntaminants n r near the grund surface can als be disslved int grundwater. Grundwater discharge carries sluble materials such as nitrate int streams

19 Chemical Cntaminants Bth natural and man-made Natural Cntaminant Examples: Weathering f rck: Arsenic Uranium Barium Sea water intrusin: Salt Man-made Cntaminant Examples: Rad salt Fertilizer (nitrate) Pesticides Oil r gas spills

20 Bacterial Cntaminants Pse mst serius health threat frm drinking water. Often frm inadequate wells r septic systems Pr Well Cnstructin / Maintenance Can allw the entry f surface r nearsurface surces f bacteria frm sils r frm septic systems Leaking septic tanks Mst cmmn surce f E. cli cntaminatin

21 High Capacity Wells and Sea Water Intrusin Factrs affecting sea water intrusin Lcal gelgy/hydrgelgy Surface elevatin/fresh grundwater level Wells Distance frm shre Pumping rate and duratin f pumping PEI sea level rise study Sea level rise will nt impact sea water intrusin significantly Pumping by high capacity wells within a few hundred meters f the cast is much greater issue Image: USGS Water Act Cnsultatins Fall

22 Estuary Anxia Nutrients cause excess plant grwth (sea lettuce). Sea lettuce mats suffcate ther life When sea lettuce dies, decay prcess uses up xygen, causes disclratins and durs(anxic events). Water Act Cnsultatin Fall

23 Occur annually Anxic Events early summer t fall happening earlier, lasting lnger, even int fall Nutrient / circulatin relatinship Nutrient = nitrate Nrth shre has naturally small tides - less flushing Addressing Anxic Events: Flushing Very little can be dne as causeways and bridges that restrict flw have been fixed Other issues (e.g. sills that restrict circulatin) are addressed as structures are repaired/replaced. Nutrient lading Reductin f nitrate lads needed Harvest nt a slutin High cst Wuld need t be cntinuus As sn as stpped, sea lettuce grws back By-catch f ther species Nt sustainable- currently n way t ffset csts Water Act Cnsultatin Fall

24 Nitrate in Surface Water Aquatic Life Guideline Sme systems are abve fresh water aquatic life guideline Mstly frm grundwater Run-ff a smaller prprtin Slight decline in levels in mst steams in the last few years Water Act Cnsultatin Fall

25 PEI Surces f Nitrate Agriculture Backgrund Septic Municipal Industrial Water Act Cnsultatin Fall

26 m High Capacity Wells - Nitrate High capacity well Decreasing Nitrate Cncentratin With Depth Fewer & Smaller Fractures With Depth ~75% f water cmes frm tp 20 m High capacity wells d nt draw nitrate deeper int the aquifer Water Act Cnsultatin Fall

27 Nitrate Reductins Required (%) Science based methd fr setting targets develped. Addresses bth estuary and drinking water issues Mst f the prvince needs n reductin in leaching. Mst areas that need reductin need a significant amunt f reductin Water Act Cnsultatins Fall

28 Siltatin Impacts n fish and aquatic life Difficulty finding prey fd Pr respiratin Pr reprductin Opprtunity Success Mnitring effrts have nt captured the full extent f the issue Current research by UPEI/ CRI t make recmmendatins fr mnitring methds (expected early 2016) Expected that cntinuus (autmated) mnitring will be a crnerstne Water Act Cnsultatins Fall

29 Fish Kills (dcumented) Pesticide cause Water Act Cnsultatin Fall

30 ng/ml Pesticide Detectins per River Surface Water Pesticides Surface Water Pesticide Detectins Max Detectins vs. Lng Term Guidelines (Canadian Water Quality Guidelines fr the Prtectin f Aquatic Life) All 9 rivers had at least ne detectin Guidelines fr 4 pesticides detected Withut Guidelines: River Metalaxyl, Clthianidin, Thiamethxan, Chlrantranilprle, Hexazinne Atrazine Imidaclprid Linurn Metribuzin Pesticide Cmpund Detected Value (max) Guideline Value Water Act Cnsultatin Fall

31 Bacteria Apprved Cnditinally Restricted Restricted Prhibited Impact is n the shellfishery Cntaminatin dictates where bivalve shellfish may be harvested. Surces Sme are natural Birds Seals Mstly related t human activity Livestck/manure Urban run-ff Municipal wastewater effluent Water Act Cnsultatins Fall

32 Climate Change Glbal temperatures are rising Impacts Rising sea levels Less winter ice Precipitatin Strnger events Similar verall amunts but a bit mre in the near future (bit less in lng-term) Less snw yet mre precipitatin in winter; less precipitatin in summer Adaptatin crucial but challenges f uncertainty in impacts Grundwater impacts are unclear Changes in timing f recharge with less winter snw Amunt f recharge verall change may be minimal? Rising sea levels will have negligible impacts n sea water intrusin Surface water impacts Baseflw timing change spring freshet timing change High strm run ff events mre frequent Water Act Cnsultatin Fall

33 Water Management Tls Watershed Management Land Use Planning Water Cnservatin Water Security Reginal Cumulative Effects Water Supply Planning Ecnmic Develpment Challenges Water Act Cnsultatin Fall