Contaminant Fate and Transport - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 288

Surface water bodies under advisory because of one or more contaminants include
(USEPA 2008a)

• 43% of the nation's total lake acres (excluding the Great Lakes), representing
approximately 7.3 million ha (18 million ac) of surface water
• 39% of the nation's total river miles, or approximately 2,250,000 km (1.4 million
miles)
• 42% of the nation's contiguous coastal waters
• 100% of the Great Lakes and their connecting waters

Figure 8.6 shows the number of advisories in each state and the states issuing statewide
advisories in 2008 (USEPA 2009b). Every state had at least one advisory in 2008. Figure 8.7
shows the number of advisories by contaminant. Please note the sharp increase in the area
of surface water covered by PCB and mercury advisories, while there has been relative
areal stability for DDT, dioxins, chlordane, and others (USEPA 2009b).

8.3.5 Fate and Transport of Contaminants in Groundwater

Transport of contaminants in groundwater is dominated by three factors: advection,
dispersion, and molecular diffusion. When applied to groundwater, advection is the
movement of contaminants by the bulk motion of groundwater flow, dispersion is the
tendency for contaminants to spread out from the path of the expected advective flow,

36

17

48 5

MA= 177
RI = 23
CT= 21
NJ = 104
DC= 1
DE= 30
MD= 77

12 12

1203

19

19

382

8

157

5

215

115

11

40

7

128

18

80 251

66 27

19

58

8 11

17

14

30

6

14

22 69

33 Legend

49 150

16

No statewide
freshwater advisories

34

52

Statewide advisories
for freshwater
Statewide advisories
for lake
Statewide coastal
advisories

317

1

AK

Puerto Rico

Guam

AS

HI Virgin islands

0

0

1

4

4

FIGURE 8.6
Health advisories for bioaccumulative contaminants in surface water by state. (From United States Environmental
Protection Agency (USEPA), Biennial National Listing of Fish Advisories for 2008 , EPA-823-F-09-007, Washington,
DC, 2009b.)