9343 - Laserfiche WebLink

Home Browse Search

25 4.0 CADMIUM ARSENIC ~ ~ Z<l: 3.5 .---------------------------------- Z<l: 20 -0: -0: -t:) zt:) Zo: 3.0 Qo: QUJ 2.5 ~~ 15 I-: a.. <l:CIl o:~ ~~ 2.0 t-<l: Zo: 10 Z<l: ~t:) UJo: 1.5 Ut:) zO ZO 1.0 . . . ... . ................ 00: 5 00: U~ U~ ~ ~ 0.5 0 0 1960 1965 1970 1975 1980 1985 1990 1995 2000 1960 1965 1970 1975 1980 1985 1990 1995 2000 100 250 ~ 90 ~ Z<l: Z<l: _0: 80 -0: 200 -t:) -t:) Zo: 70 Zo: QUJ QUJ ~a.. 60 ~a.. 150 o:CIl 50 o:CIl t-~ t-~ z<l: 40 Z<l: 100 UJo: UJo: Ut:) 30 Ut:) ZO ZO 00: 20 00: 50 U~ U~ ~ 10 ~ 0 0 1960 1965 1970 1975 1980 1985 1990 1995 2000 1960 1965 1970 1975 1980 1985 1990 1995 2000 350 0.6 ~ LEAD ~ MERCURY z<l: 300 Z<l: 0.5 _0: _0: ----------------------------------- -t:) -t:) Zo: 250 Zo: QUJ QUJ 0.4 ~a.. 200 ~a.. o:CIl o:CIl 0.3 t-~ t-~ 1\..... Z<l: 150 Z<l: UJo: UJo: ,.. Ut:) Ut:) 0.2 ZO 100 ---------------------------------- ZO r 00: 00: ..J U~ 50 U~ 0.1 ~ ~ ~ 0 0 1960 1965 1970 1975 1980 1985 1990 1995 2000 1960 1965 1970 1975 1980 1985 1990 1995 2000 ESTIMATED YEAR OF DEPOSITION 7,000 ~ Z<l: 6,000 _0: EXPLANATION -t:) Zo: 5,000 QUJ -------- PROBABLE EFFECT LEVEL (PEL) ~a.. 4,000 INTERIM SEDIMENT QUALITY GUIDELINE (ISQG) o:CIl t-~ 3,000 z<l: UJo: Ut:) 2,000 ZO 00: UU 1,000 ~ ---------------------------------- 0 1960 1965 1970 1975 1980 1985 1990 1995 2000 ESTIMATED YEAR OF DEPOSITION Figure 4. Concentrations of selected trace elements in Dillon ReseNoir core DLN (taken near dam August 1997) compared to the Canadian Sediment Quality Guidelines. [Concentrations below the ISQG are not expected to be associated with any adverse biological effects. Concentrations between the ISQG and the PEL represent a range in which adverse biological effects are occasionally obseNed; concentrations above the PEL are expected to be frequently associated with adverse biological effects (Canadian Council of Ministers of the Environment, 1999).] IDENTIFICATION OF WATER-QUALITY TRENDS 13