UNITED STATES GEOLOGICAL SURVEY 

0 . 

' 

SELECTED TRACE-ELEMENT AND 

ORGANIC CONTAMINANTS IN 

STREAMBED SEDIMENTS OF THE 

POTOMAC RIVER BASIN, AUGUST 1992 

(~c~ By James M. Gerhart and 

l0 R L Joe/ D. Blomquist 

'-\'\ o q s -lf d. lo; 

ABSTRACT 

This report describes the occurrence and distribution of five selected 

contaminants in streambed sediments 

at 22 stream sites in the Potomac 

River Basin. Lead, mercury, and total 

DDT (dichlorodiphenyltrichloroethane) were detected at all sites, and 

chlordane and total PCB's (polychlorinated biphenyls) were detected at 

most sites. At six sites, streambedsediment concentrations of contaminants were detected at levels with the 

potential to cause frequent adverse 

effects on aquatic organisms that live 

in the sediments. Chlordane was 

detected at these high levels at sampling sites on the Anacostia River, the 

North Branch Potomac River, Bull 

Run , and Accotink Creek; mercury 

was detected at these levels at sites 

on the South River and the South 

Fork Shenandoah River; and total 

PCB's were detected at these levels 

at the site on the South Fork Shenandoah River. The highest concentrations of all five contaminants generally 

occurred at sampling sites downstream from areas with industrial 

plants, urban centers, or orchard and 

agri cultural activity. The occurrence 

of these contaminants in streambed 

sediments of the Potomac River Basin 

is of concern because the contaminants (1) are environmentally persistent, (2) are available for downstream 

transport during high streamflow periods, and (3) have the potential to 

cause adverse effects on the health of 

aquatic organisms and humans 

through bioaccumulation. 

INTRODUCTION 

Background 

The U.S. Geological Survey ( SGS) 

is implementing the ational WaterQuality Assessment ( AWQA) program 

to de cribe and xplain water-quality conditions and trends of the Nation ' urfacewater and grou nd-water resources 

(Gilliom and others. 1995). One of the 

fir. t areas to be studied as part or the fullsca le A WQA program i. the Potomac 

Ri ver Basin. where water-quality 

sampling acti vities for the study 

were begun in 1992. A major goal 

of the Potomac Ri ver Bas in tudy i 

to describe the ccurrencc and di stribution of a wide variety of phy. ica l, chemi cal, and bi ological waterquality characteri . ti c of treams 

and ground water in the bas in. 

Some of the chemical compound of interest in the WQA 

program. including many trace clements and syntheti c organic compound . . do not easil y di s. ol e in 

streamwater. but in tead tend to 

accumulate in trcambed s diments 

and aquati c biologica l ti ssues. 

When these comp unds accumulate 

in ufficientl y high concentrations 

in sediment or ti ue , they can act 

as contam inant that can adver. ely 

affect the hea lth of aquati c organi m . To addre the occurrence 

and di stributi on of selected traceelement and organic contaminant · 

in streams in the Potomac Ri ver 

Ba in, a survey of contaminants in 

streambed sediments and aquatic 

b. ·cal ti sues was conducted in 

MAY 2 8 1996 

SR 

lfBRAR Y 

This report pre ellls the re ult of a 

urvey of contaminants in streambed edimelll in selected stream of the Potomac 

Ri ver Ba in. The report focuses on five 

elected contaminants, including two trace 

element - lead and mercury-and three 

organic compound hl01·dane, total 

DDT (di chlorodiphenyltrichloroethane). 

Streambed-sediment samples were collected and 

composited from a variety of depositional settings 

within stream reaches that averaged 300 feet in 

length at each sampling site. 
and total PCB' 

(pol ych I ori nated 

bi phenyls). Lead, mercury, 

chlordane, and total PCB 's were 

selected becau e these compounds have been designated as 

"tox ics of concern" by the 

Chesapeake Bay Program 

(Che apeake Bay Program, 199 I a); 

total DDT wa elected becau e of 

nati onal concern regarding its environmental effect durin g the Ia t several 

decade . The report de cribes the re ult 

of treambed- edi ment ampling at 22 

tream site throughout the Potomac 

River Ba in in Augu t I 992, and addre -

e the fo llowing questi ons about the 

occurrence and distribution of the five 

contami na nt in streambed sediments of 

the ba in : 

( 1) Which stream ite have streambed sediments with elevated concentrations of 

these contaminants? 

(2) What i the relation between elevated concentrations of these contaminant in 

treambed ediments and potenti al 

up. tream contaminant sources? 

Physiographic Provinces 

Appalachian Plateau 

Great Valley subprovince 

D BlueRidge 

Piedmont 

• Triassic Lowlands subprovince 

D Coastal Plain 

17 • Location and number of sampling site 

(3) What are some of the important environmental implications of the occurrence of 

these contaminants in streambed sediments? 

Streambed-Sediment Sampling 

and Analysis 

The sampling site that were selected 

for a sessing the occurrence and distributi on of contaminants in streambed sediments in the Potomac Ri ver Ba in cover a 

range of phy iographi c ettings (fig. I), 

tream izes (table I), and land u es. 

Drainage areas for the 22 sites generall y 

range from about 20 to I 2,000 square 

mil e (tabl e I), and incl ude parts of the 7 

physiographi c prov inces and subprovince 

and parts of the fo ur States in the 

2 Contaminants in Streambed Sediments 

Figure 1. Streambed sediments were sampled in August 1992 at 22 stream sites in the 

14,670-square-mile Potomac River Basin. 

0 10 20 30 40 50 MILES 

0 10 20 30 40 50 KILOMETERS 

Potomac Ri ver Basin (fig. I). 

At each of the 22 sampling sites, 

fine-grained streambed sediment were 

collected and compo ited from a vari ety 

of depositional setting within stream 

reaches that averaged about 300 feet in 

length . Sampl es were coll ected from the 

top I inch of fine-grained sediments u ing 

a scoop in wadeabl e streams or a dredge 

in deeper streams; sampling equipment 

was con tructed from inert materi als. All 

sites were sampled during low streamflow 

conditions when no fine-grained sediments were in suspension in the water 

column. Each ampl e was sieved into 

subsampl es in the field fo r laboratory 

analy i . 
Table 1. Streambed-sediment sampling sites in the Potomac River Basin, August 1992 

Sampling 

site 

number Station number Station name 

North Branch Potomac River at Steyer, Md. 

Savage River near Barton, Md. 

North Branch Potomac River at Pinto, Md. 

Drainage 

area, in 

square 

miles 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

01595000 

01596500 

01600000 

01603000 

01608000 

01611500 

01614500 

01616500 

01617800 

01618000 

01625000 

01627500 

01631020 

01634000 

01636500 

01639000 

01644000 

01651010 

01652589 

01654000 

01657000 

01661050 

North Branch Potomac River at Cumberland, Md. 

73.0 

49.1 

596 

875 

283 

677 

494 

272 

South Fork South Branch Potomac River near Moorefield, W. Va. 

Cacapon River near Great Cacapon, W. Va. 

Conococheague Creek at Fairview, Md. 

Opequon Creek near Martinsburg, W. Va. 

Marsh Run at Grimes, Md. 

Potomac River at Sheperdstown, W. Va. 

Middle River near Grottoes, Va. 

South River near Harriston, Va. 

South Fork Shenandoah River below Cabin Run at Front Royal, Va. 

North Fork Shenandoah River near Strasburg, Va. 

18.9 

5,936 

375 

212 

1,647 

768 

Shenandoah River at Millville, W.Va. 

Monocacy River at Bridgeport, Md. 

Goose Creek near Leesburg, Va. 

Anacostia River near Bladensburg, Md. 

3,040 

173 

332 

130 

Potomac River below Oxon Creek at Alexandria, Va. 

Accotink Creek near Annandale, Va. 

11 ,880 

23.5 

147 

18.5 

Bull Run near Manassas, Va. 

St. Clement Creek near Clements Md. 

amples for trace-element ana lysi 

were sieved through a 63-micrometer 

nylon filter, digested to complete di ssoluti on. and analyz d for 45 trace eme nt . 

Lead wa.· determined by inducti ely coupled pia ma-atomic emiss ion . pectrometry (Bri ggs, 1990). and mercury was 

determined by cold apor-atomi c absorpti on ·pectrophotometry (O'Leary and others. 1990). Samples for rganic-compound analysis were sieved through a 2-

millimeter stainless-steel sieve and analyzed for 40 organochlorine compounds. 

80 s · mi volatile organi c compounds. and 

all P 8 congeners b the M ethods 

Development Program of the U 

National Water-Quality Laboratory in 

Arvada, olo. Ch lordane. total Dl T. and 

total P B's were determined by dual capillary-column gas chromatography with 

eleCll·on-capture detection (Foreman and 

other . 1995). 

OCCURRENCE AND 

DISTRIBUTION OF 

SELECTED CONTAMINANTS 

The occurrence of the fi ve selected 

contaminant in streambed sediment of 

the Potomac Ri ver Bas in generally correlate with their u e in the basin by man 

for a variety of 1 urposes (tabl e 2). The 

uses f many of these contaminants ha e 

been regulated r bann cl in the last several decade because of an incrca ·eel a1 arcne. of the ad erse effect they can have 

on animal and human health. ome of 

their adver e effect on human hea lth are 

li. ted in table 2. 

The unit of streambed-sediment concentration u. ed in thi report are part per 

million (ppm) for trace elements and parts 

per bi llion (ppb) for organi compounds. 

Pans per million are equivalent to milligram per kilogram of dry sediment, and 

part per billion are equi valent to microgram per kilogram of dry sediment. 

Streambed-sediment concentrations of the 

three organic compounds (chlordane. tout! 

DDT. and total P B · ) are the sum of the 

concentrati ons of several related compounds. hlordane concentrati on is the 

sum of cis-chlordane, tran -chlordane. 

oxychlordane, ci:-nonachlor, and transnonachlor concentrati ons. Total DDT 

con entration i the Lllll of o,p'-DDT. 

p.p'-DDT. o,p'- DDE, p,p'-DDE. o.p'-

DDD. and p.p'-DDD concentration . 

Tota l PCB c ncentration is the sum of the 

concentrations of all the P B congener · 

that were detected. The laboratory considered the concentrati ons of indi vidual 

chlordane and DDT compound to be c. timatcs if the concentration. detected were 

lc s than the laboratory"s re1 orting limits. 

In thi s report . the sums of concentrati ons 

Contaminants in Streambed Sediments 3 
Table 2. Summary of Information on five selected contaminants sampled in streambed sediments, Potomac River Basin, August 1992 

NO, not detected 

Lead Batteries; pipes U..ln pelnta, gasoline, Damage to nervous system, 

end plumbing; ..tiNd ehot now llmJIMI, kidneys, brain; fatigue; 

vehicle emissions; anemia; paralysis; fetal brain 

paint lngracllants; damage; possible cancer. 

solder; corrosion 

of brass; natural 

mineral deposita. 

Manufacture of DilciWge8 to-- and Damage to kidneys and 

paint, paper, and air now regulated. nervous system. 

vinyl chloride; 

batteries; 

Ingredients In 

fungicides; natural 

mineral 

Possible cancer; dizziness; 

headache; fatigue; 

and ants. conwlslons. 

Total DDT Insecticide used to Banned In 1972. Possible cancer; damage to 

control mosquitoes nervous system, liver, 

and spiders on a kidneys, skin. 

wide variety of 

crops and fruits. 

TotaiPCB'a Used In electrical Banned In 1979. Possible cancer. 

transformers and 

plasticizers. 

1 U.S. Environmental Protection Agency, 1991 ; Chesapeake Bay Program, 1991b. 

2 Porta per million = milligrams ol contaminant per kilogram ol dry streambed sediment. 

3 Parts per billion = micrograms of contaminant per kilogram of dry streambed sediment. 

1S 31 110 4.0 

0.09 14.S 0.02 

1.0 

0.09 1.13 23.9 4 1.0.2.0 

NO 3.9 .1·.5 

limits for Individual compounds of chlordane and total DDT. Some Individual corr1poo1nds were detected at concentrations less than the reporting limit; these concentrations were 

of related compounds for chlordane and 

total DDT include these estimated concentrations. 

On the basis of analysis f reference 

standard s and duplicate samples, the laboratory analyses indica te a fair degree or 

reproducibility. Determinations of lead 

and m rcury in reference samples : h w a 

5.8-pcrccnt standard dev iation for both 

clements. The standard deviation of the 

analyses of laborat ry reference amplcs 

for chlordane and DDT compounds 

ranges from II to 23 percent. The standard de iation or the analyses or reference samples for total P 8 's is about 7 

percent. 

Because or the many complex factors 

involved in bioaccumulation processes, 

contaminant concentrations in streambed 

sediments cannot be used as direct measur s of the potential or the contaminant s 

to cause adverse effects on human health. 

Howe cr, it is pos.· iblc to relate sed iment 

concentrati ons to the potential for ad crsc 

cf"fects on the hea lth of aq uati c organisms 

that li ve in th e~ ·climents. Long and others ( 1995) and ong. and M organ ( 1990) 

established sediment-qual ity guideli nes 

useful for thi s purpo. c by relating contaminant concentrations in streambed sediments to observed adverse effects on 

aq uati c rgani sms for a large number or 

studies in e. tuaries and bays or orth 

A meri ca. Two concentrati ons were 

defined- Effects Range-Low (ERL) and 

Effects Range-M edian (ERM )- which 

divide the range or contaminant concentrations and their potential effects on 

aq uatic organi sm into three ban Is 

(table 3). Sediment concentrati ons in the 

fiL t band (less than the ERL va lue for the 

ind icated contaminant) rarely cause 

adverse effccL· on organi sms that l ive in 

the sediments. concentrations in the middle band (between the ERLand ERM va lues) occas iona lly cause adverse effects, 

and concentrations in the third band 

(greater than the ERM value) frequently 

cause adverse effects. 

Long and Morgan's ( 1990) ERLand 

ERM values for chlordane were not 

updated by Long and others ( 1995); conseq uentl y, the ch lordane guidelines presented in tab le 3 probably shou ld be 

applied with more cauti on than the guidelines for lead, mercury. total DDT, and 

total PCB's. T he edimcnt-qual ity guidelines for al l fi ve contaminants arc used in 

4 Contaminants in Streambed Sediments 

I 

thi s report to estimate the potential for 

adverse effects on aq uati c organi sm. 

posed by the measured contaminant concentrati on · in the streambed-sediment 

samples. It should be noted that these 

guidel ines can only serve as informal preliminary screening tools for streambed 

sed iments in freshwater strea ms. and do 

not replace the need for tox icity testing to 

determine specifi c adverse effects on 

aq uatic organism . . 

Trace Elements 

The concentrations of lead and mercury discussed in thi s report repre ent the 

sum or the naturall y occurring elements 

contained in the mineral grains of the sediments and the element attached to the 

mineral grains a a re ult or contamination from human activities. To obtain an 

estimate of the proportion of the lead and 

mercury due to contamination, the proportion contained in the mineral grains was 

determi ned from compari sons to worldwide averages of elemental concentrati ons 

in the Earth 's crust, or average cru stal 

abundances. Fyfe ( 1974) computed the 

average cru stal abundances or lead and 

mercury to be 13 ppm and 0.08 ppm, 
Contaminant 

Lead 

Mercury 

Chlordane 

Total DDT 

Total PCB's 

' Long ond others (1995) 

' Long and Morgan ( 1 990) 

140 

120 

ERL- ERM 

Occasional 

adverse 

effects 

on 

aquatic 

organisms 

Lead a. , 

a>c 

~ ,g 100 

g)E 

~ ~ 80 .!: C/) 

ct:: 

0"' 

~ ~ 60 

c ·-:. .,"' § i 40 

u:.O 

m ~ 20 _J 

Potential frequency of occurrence 

ol adverse effects on aquat•c 

orgamsms as a result of lead 

concentrat•ons •n bottom sed•ments 

(l ong and others. t 995): 

Mop Bar graph 

• Frequent • 

• Occasional 

• Rare • 

• Not detected ND 

Not analyzed NA 

Figure 2. Lead concentrations in streambed sediments at all sites exceeded the average crustal 

abundance value for lead; concentrations at four sites exceeded the Effects Range-Low (ERL) 

value. The four sites where lead concentrations in streambed sediments exceeded the ERL 

value are near urban areas in Washington, D.C. (sites 18-20), and Cumberland, Md. (site 4). 

respec tively. In the discuss ions of lead 

and mercury concentrations in streambed 

sediments that follow, these average 

cru stal abundances of lead and mercury 

arc used to provide a frame of reference 

for the pr portion of lead and mercury 

that might be related to c ntamination. 

Lead 

Streambed-sediment sample coll ecteel at all sites where lead was analyzed 

had lead concentrations that excccclccl thc 

average crustal abundance of lead of 13 

ppm. indica ting that the occurrence of 

lead in these streambed sediments may be 

related to contamination by human acti vities (fi g. 2a). one of the sites had a lead 

concentration that exceeded the ERM 

value of 2 18 ppm for lead. However, 

streambed sediment at 4 or 2 1 ·ites had 

lead concentration. that exceeded the 

ERL va lue of 46.7 ppm, the level above 

218 ppm1 

l 0 .71 ppm 

16.0 ppb2 

wh ich the potential ex ists for occasional 

adverse effects on aquati c organi sms that 

li e in the sediments. 

Three of the four , itcs where lead 

concentration in streambed sed iment s 

exceeded the RL value ar~ ncar Washington, D. .- site I on the nacosti a 

Ri ver. site 19 on the Potomac Ri ver. and 

. ite 20 on Accotink reck; the fourth site 

i. itc 4 on the onh Branch Potoma 

Ri ver (fi o. 2b). The highest I ad concentration ( II 0 ppm) was detected in s diment from . ite 18 on the A nacostia 

Ri ver, j ust northea t of Washington , D.C.. 

wh ich drains an intensi ely developed 

urban area. Streambed sediment at site 

19 on the Potomac River clown tream 

from Wa hington, D.C .. had a lead concentration of 5 1 ppm; the streambed sediments at thi s site repre cnt a composite of 

materi als cleri ved from I 1.880 . quare 

miles of P tomac Ri ver Bas in drainage 

area . The lowe t lead concentration ( 15 

ppm) was detected in trcambccl sediments from site 9 on Marsh Run. which 

drains a sma ll, relati vely unpopul ated and 

highly agri cultural watershed. 

Mercury 

The median mercury concentration in 

streambed-sed iment samples collec ted at 

sampling sites where mercury was analyzed was 0.09 ppm (about the same as 

the a crage cru tal abundance of mercury 

of 0.08 ppm). but the range of concentrations wa large. with a maximum va lue of 

14.5 ppm (fi g. 3a), more than 150 times 

greater than the median. trcambecl sediments at six of the site. had mercury concentrations greater than twice the average 

cru stal abundance va lue, indicating probable mercury c ntaminati n. Of these six 

sites, two had mercu ry concentrations that 

exceeded the ERM value of 0.7 1 ppm for 

Contaminants in Streambed Sediments 5 
"0 

Q) 

"Ea 

r---------------* ~ 0. 

~ ~ 0. Mercury a. c (I) 

~[ 0. 

13 .E. 0. u (/) 

g ~ 0. u E 5'0 

~ ~ Q) 

::;: 

ERM 

Streambed-sediment sampling site number 

Pot'ential frequency of occurrence 

of adverse effects on aquatic 

orgamsms as a result of mercury 

concentrat•ons 10 bottom sed1ments 

(Long and others, t995) 

Bar graph 

Froquont II Occasional 

Rare II Not detected N D 

Not analyzed NA 

Figure 3. Mercury concentrations in streambed sediments at many sites generally were at or 

near the average crustal abundance value for mercury; concentrations exceeded the Effects 

Range-Median (ERM) value at two sites and the Effects Range-Low (ERL) value at four other 

sites. The six sites where mercury concentrations in streambed sediments exceeded the ERL 

or ERM values are in the Shenandoah River Basin (sites 12, 13, and 15) and urban areas in 

Washington, D.C. (sites 18 and 19), and Cumberland, Md. (site 4). 

mercury, the level above whi ch the potenti al ex ists for freq uent adver e effects n 

aquatic organi sms that li ve in the sediment s. 

The 1 wo sites where mercury concentrati ons in streambed sed iments exceeded 

the ERM aluc for mercury-site 12 on 

the South Ri ver and site 13 on the South 

Fork , h nandoah Ri ver-are located in 

the Shenandoah Ri ver Bas in (fi g. 3b). 

The highest concentration of mercury was 

14.5 ppm in streambed cd im nts at site 

12 on the South Ri er, fol lowed by 0.86 

ppm at site 13 on the outh Fork 

Shenandoah Ri vcr an I 0.46 ppm at site 15 

on the henandoah River. Since 1979, 

the Virginia Water ontrol Board (now 

th Virginia Department of "Iwironmcntal 

Quality) has conducted several . urvcys 

for mercury in streambed sediment. ncar 

sites 12 and 13 (C.T. Mizell , Virginia 

l cpartmcnt of nvironm mal Qualit y, 

wriucn commun ., 1995). Th ir . urveys 

also have detec ted 111 rcury in streambed 

sediments at concentrations that exceeded 

the RM aluc for mer ury. although the 

con ·entrations in their surveys arc not as 

high as the concentrations in the 1992 

·ur cy. The irginia Department or 

Three other sites that had mercury 

concemrations that exceeded the ERL 

aluc for mercury are site 18 on the 

Anacostia River, site 19 on the Potomac 

Chlordane 

River, and site 4 on the orth Branch 

Potomac River; all three ite are downstream from major urban area . 

S diment from site 19 on the Potoma 

River downsu·eam from Washington, 

D.C., had a mercury concentration of 0.17 

ppm, about twi ce the median concen u·ation for the 2 1 sampled ite . Site 5 9, 

16, and 22, wh ich had the lowe t mercury 

concentrations-le than 0.05 ppmdrain relatively undeveloped areas that are 

mainly characterized by fore t and farm -

land. 

Organic Compounds 

Unlike lead and mercury and other 

trace elemen ts that occur in streambed 

sediments, and whi ch can be derived from 

natural mineral source a well a contamination from human activitie , the 

occurrence of chlordane, total DDT, and 

total PCB's in streambed sediment can 

onl y result from contamination from 

human acti itie . In the following di. cussions of the concentrations of these three 

organic compounds, streambed sediment. 

at ampling sites where the compounds 

were detected are considered to be contaminated to some degree. 

Chlordane 

At the 13 sites where chlordane was 

detected in streambed sediments, the cont4 r--------'"""':'--..., 

a. a:: t2 .0 

Ec: 

roo 

~~ 10 

.!: ~ 

g ~ 8 "" t:: 

~a. "' "' ~ .!:_ 61---11--------1 ... c: (/) 

8~ 

~ .£: 4 ro-o -oG> 

~ (/) 

0 

:c 

(.) 

Potent•al frequency of occurrence 

of adverse effects on aquat•c 

organisms as a result of chlordane 

concentrat•ons in bottom sediments 

(Long and Morgan. t990) 

Bar graph 

Frequent Ill Occasional 

Rare -

Not detected N D 

Not analyzed NA 

nvironmcntal Quality is continuing to 

monitor mercury contaminati on at these 

sites through periodic collec tion and 

ana lysis or fi sh ti ssues . 

Figure 4. Chlordane concentrations in streambed sediments were detected at 13 sites; concentrations at 4 sites exceeded the Effects Range-Median (ERM) value. Seven of the 13 sites where 

chlordane was detected in streambed sediments are located in the Great Valley (sites 7, 8, 11 -15); 4 

are in the Washington , D.C., area (sites 18-21 ), and 2 are in the Cumberland, Md., area (sites 3-4). 

6 Contaminants in Streambed Sediments 
"0 

~ E c 

~-----------------, ERM • 46.1 ppb 

20 

Ri er Ba in, had a hi rdane concentrati on (3.39 ppb) that wa b 1v ccn th ERL 

and ERM alu . . ite 4 on the onh 

Branch Potoma Ri cr had str amb d Total DDT a. ::lg 10 

~ ~ 5 ::===:::::======~ edim nts with a chi rdan cone ntration 

. S ~ 4 that ex eeded the - RM va lu ' . 

g~ 

"'"' ~a. 

s 

g~ ..,., 

1-E 

g~ 2 

-"' "' 

~ 

Potential frequency of occurrence 

of adverse effects on aquatic 

organisms as a result of total DDT 

concentrations rn bottom sedrments 

(Long and others. t995) 

Bar graph 

Frequent II Occasional 

Rare Ill Not detected N D 

Not analyzed NA 

Total DDT 

T tal DDT cone ntrations in str ambed sed iments at sc en sites ex cede I the 

RL va lue of 1.58 ppb fort tal DDT (fig. 

Sa). The highc t total DDT cone ntrati n 

in sed iment (23.9 ppb), although 15 

time. greater than the RL value, was 

only about one-half the ERM value of 

46. 1 ppb for total DDT. Total DDT concentration. in . trcamb d sediments at I 0 

of the 22 itc. were I ss than I ppb. 

Of the seven site. that had total DDT 

concentrati on exceeding the ERL va lu ', 

fi e ites ar in the Great Valley- site 7 

on on co hcaguc Creek, site 8 on 

Opcquon reck, site II on the Middle 

Ri ver, site 14 on the orth Fork 

Figure 5. Total DDT was detected in streambed sediments at all sites; concentrations exceeded 

the Effects Range-Low (ERL) value at seven sites. Five of the seven sites where total DDT con· 

centrations in streambed sediments exceeded the ERL value are in the Great Valley (sites 7, 8, 11 , 

14, and 15). 

hcnandoah R i vcr, and sit I 5 on the 

Shenandoah Ri cr (fig. 5b). The second 

hi ohest total DDT concentration detected 

in streambed sediments was 15 ppb at sit ' 

I 5 on the Shenandoah Ri cr, which drains 

200 r---------~------~ 

centrations ranged from 1.67 to 66.6 ppb 

(rig. 4a). Four itcs had streambed sediment. with chlordane concentrations that 

exceeded the ERM aluc of 6 ppb for 

chlordane. The other nine site where 

chlordane was detected in streambed sediments had concentrati ons less than the 

ERM value, but greater than the ERL 

va lue of 0.5 ppb. Chlordane was not 

detected a1 9 of the 22 sa mpled sites. 

Chlordane was detected in streambed 

sed iments at itcs 7, 8, and 11 - 15 in the 

inten ivcl y fanned Great Valley; fi ve of 

these sites are in the Shenandoah Ri ver 

Ba. in (fi g. 4b). Site I , 20, and 2 1 on 

stream · in the heav ily urban Washington, 

D.C., area had trcambcd . cdimcnts with 

chlordane concentrati ons that exceeded 

the ERM value. The chlordane concentrati on (66.6 ppb) in strea mbed sediments 

at site 18 on the Anacosti a Ri ver was 

more than I 0 times greater than the ERM 

va lue. Thi s high chlordan concentration 

in streambed sediments at . ite 18 i · corroborated by lreambed-. cdiment samples 

collected by Wade and others ( 1994) at 

ix sites several miles downstream from 

site I , where chlordane concentrati ons in 

. ediments ranged from 28 to 140 ppb. 

The sediments at site 19 on the Potomac 

Ri ver. which !rains most of the Potomac 

Total PCB's 

180 ~----...f~---.... ERM 

160 

140 

~ 120 

~ 100 

a. 'g c 80 L------..&.----~ 

~ g 28 .-------- ---- ---.., 

~~ 

E ~ 24 1------ - -+--- ~~ 

~ ~ 20 

.!: [ 16 

"'c Co ·-

u 12 n. 

8 

4 

~~~~~~ ~ 

Paten !tal frequency of occurrence 

of adverse effects on aquatic 

organisms as a result of total PCB 

concentrations 10 bottom sediments 

(Long and others, t 995) 

Bar graph 

Frequent II Occasional 

Rare -

Not dolected N D 

Not ana lyzed NA 

Figure 6. Total PCB's were detected in streambed sediments at 17 sites; concentrations exceeded 

the Effects Range-Median (ERM) value at 1 site and the Effects Range-Low (ERL) value at 2 other 

sites. Concentrations of total PCB's in streambed sediments were highest at site 13 on the South 

Fork Shenandoah River, site 18 on the Anacostia River, and site 1 0 on the Potomac River at 

Shepherdstown , W.Va. 

Contaminants in Streambed Sediments 7 
nearly all of the henandoah Ri ver Ba in. 

The other . ite in the central part of the 

P tomac Ri ver Basin where the total 

DDT concentrati on in streambed sediment. exceeded the ERL value is ite 6 on 

the acapon Ri ver, which drain. an area 

that is mostly forested and undeveloped, 

but which ha ome agricultural acti vity. 

The. treambed. ed imen ts at ite 18 on the 

Chlordane 

naco tia River had the highe. t total 

DDT c ncentrarion in the Potomac Ri ver 

Basin ; the con entration at thi ite, which 

drains a highly urban area, wa. 23.9 ppb. 

Streambed ·ed iment at five site. in the 

we ternmost part of the Potomac Ri ver 

Bas in had total DDT oncentration. that 

were le than I ppb. 

EXPLANATION 

Total PCB's 

Streamb d sediments at only one site 

had a total PCB concentration that 

exceeded the ERM value of 180 ppb for 

total P B '. (fig. 6a). Two other site · had 

streambed ediment with total PCB concentrations that exceeded the ERL value 

of 22.7 ppb but were le . than the ERM 

value. Total PCB concentration at the 

Urban land use (from USGS GIRAS data base) 

• Orchard land use (from USGS GIRAS data base) 

.A. Site with elevated contaminant levels 

[J Industrial discharges greater than or equal to 1 million gallons per day 

(from U.S. Environmental Protection Agency STORET data base) 

Contaminants shown in RED were detected in streambed sediments 

at concentrations that exceeded the Effects Range-Median values. 

Contaminants shown in were detected in streambed sediments 

at concentrations that exceeded the Effects Range-Low values by a significant 

amount, but were less than the Effects Range-Median values. 

Figure 7. Mercury and total PCB contamination at sampled sites probably is related to industrial point sources in upstream areas; chlordane and lead contamination probably is related to urban nonpoint sources, and most total DDT contamination probably is related to 

orchard and cropland applications. 

8 Contaminants in Streambed Sediments 
other 14 ites where total PCB's 

were detected, were less than onehalf the ERL value. PCB 's were not 

detected in streambed sediments at 4 of 

the sampled site . 

The highest concentration of total 

PCB 's in streambed sed iments was 468 

ppb at site 13 on the South Fork 

Shenandoah Ri ver (fig. 6b). The Virginia 

Water Control Board sampled streambed 

. cd iments near thi site in 19 and al o 

detected high concentrati ons of total 

PCB's in the contaminated sed iments 

(Virginia Water Control Board. 1992). 

The sec nd highc. t concelllrati on of total 

PCB's in streambed sed iments was 13 1 

ppb at site 18 on th Anacostia Ri ver. 

which drains a highl y urban and developed area. The only other sit that had a 

total PCB concentration in streambed sediments that exceeded the RL value was 

site I 0 on the Potomac Ri ver at 

Shepherdstown, W. Va., where the total 

P B concentrati on was I 08 ppb. No 

P B's were detected in treambed sed iment. at sites 5, 16, 17, and 22, which 

drain mostl y farm land and forest areas of 

the Potomac Ri er Basin. 

SOURCES CONTRIBUTING 

TO CONTAMINATION AT 

SELECTED SITES 

There arc many possible point and 

nonpoint sources of the fi ve contaminants 

that were detec ted in streambed sediments 

at the 22 sampling sites in the Potomac 

Ri ver Bas in . Poss ible point s urccs include po rl y constructed landfills, chemica l spi ll s, and di scharge from industri al, 

municipal, and commercial water-treatment plants. Possible nonpoint sources 

inclu lc atmospheric deposition and runoff 

from agricultural, urban, and mining 

areas. It is possible that the occurrence of 

a contaminant in strea mbed sed iment. at a 

sampling site is the result of a combination of several of these source . . 

On a broad scale, it is pos ible to 

relate most of the high concentrations of 

contaminants in streambed sediment. at 

the 22 ampli ng site to three primary 

source of contamination- industri al 

point . ourccs, urban nonpoint sources, 

and orchard and agri cultural nonpoint 

source . In the following discu. sions. the 

upstream pre. cncc of one or more of 

these three primary sources is used to 

in fer th possible ausc of the contam inant concentrati ons that exceeded ERM 

va lues and mo. t of the con taminant concentrati ons that exceeded ERL value (fi g. 

7). Additional sampling and detailed 

in vesti 0 ation wou ld be necessary to determine the specifics urccs of contamination at each of these sam1 ling sites. 

Industrial Point Sources 

An indu ·trial point source. which is 

known to have released mercury into the 

environment. is located near the headwaters of the South Ri ver in the hcnandoah 

Ri er Basin. In 1977, mercury was di scovered in :oil at an industrialJiant in 

Waynesboro, a. (Brooks. 1977). 

Historical rcc rd. indi ·ate that m rcur was u. cd in industrial proc·sses at 

the plant until 1950. Two sampl ·d site. 

(fig. 7) downstream from th industrial 

plant in Waynesboro- si te I _ on th 

S uth Ri rat Harri st n. a .. and si te 13 

on the uth l·ork henan loah Ri er at 

Front Royal, Va.- had mercury con · ntrations in streambed sed im ·nt s that 

exceeded the ERM alu for mcrcur . 

The mercury cone ntrations atth 's' two 

sites, which were the highest m 'a. ured in 

th Pot mac Ri cr Basin, rcn, t th hi stori cal release of mercury into the en Ironment at the industrial plant in 

Wayn sboro. 

nother indu tri al point source. 

which is known to have released P B ·s 

into the environment. is located just 

upstream from site 13 on the outh Fork 

hcnandoa h Ri cr at Front Royal. Va . 

(fig. 7). Total I B concentration in 

streambed sediments at si te 13 was 468 

ppb, which cxc cdcd the RM va lue for 

total I B"s of 180 ppb. The industrial 

plant located ncar the site was losed in 

1989 after discovery of th release or 

P B's into the South Fork henandoah 

Ri er ( irginia Water ontrol Board, 

1992). Two other ites where total P B 's 

in streambed sed iments exceeded the ERL 

al uc may be related to indu. tri al sources 

of PCB contam inati on. Site 18 on the 

Anacostia Ri ver drains a highly urban 

area with a major industrial plant in a 

nearby up. tream area (fig. 7). itc I 0 on 

the Potomac Ri er at Shepherdstown, 

W. Va., has major industri al sources in its 

upper lrainagc area; however. no major 

Runoff from urban areas is a possible source of 

lead and chlordane contamination in streambed 

sediments. 
discharge point arc located immediately 

upstream of the sampling site and no 

known PCB point s urces are documented (fi g. 7). The source of the high total 

PCB concentration at site I 0 is unknown ; 

further data collecti on and investi gation is 

necessary to determine the source. 

Urban Nonpoint Sources 

The past u. e of chlordane for trea tment of termite infestati on in urban areas 

is a pr bable source of the high chlordane 

concentrati ons measured in streambed 

sediments in streams that drain urban 

areas. The four sites that have chlordane 

concentrations in streambed sediments 

that exceeded the ERM value for chlordane all drain maj or urban areas. 

Site 18 on the Anacostia Ri ver, site 

20 on Accotink Creek, and site 2 1 

on Bull Run all recei ve drainage 

Past pesticide applications in orchards are a possible 

source of DDT contamination in streambed sediments. 

from urban settings in the 

Washington. D.C., metropolitan area. Site 

4 on the orth Branch Potomac Ri ver 

receives drainage from the City of 

umberl and. Mel .. which i. the largest 

city in the western pan of the Potomac 

Ri ver Bas in (fi g. 7). Urban nonpoint 

~o urccs were identified by Wade and others ( 1994) as the probable source of high 

chlordane concentrations in streambed 

sediments in the A mico. tia Ri ver. and it is 

li kely that similar types of urban source · 

arc also responsible for the high concentrati ons of chlordane in streambed edimcnts at sites 4, 20. and 2 1 in thi s survey. 

The many past and pre. ent uses of 

lead in urban areas, which include leaded 

fuel for vehicles. batteries, constru tion 

pipes, plumbing onnecti ons, and paint 

ingredient s, probabl y arc th maj or 

source:-. or the relati vely high lead concentrati on detect din streambed sediment at 

site 18 on the nacosti a Ri ver (fi g. 7). 

II sampled sites had lead concentrati ons 

in streambed scdim nts that exceeded the 

average cru stal abundance of lead; the 

maj or reason for thi s 1 r bably is the 

wi Jcsprca I atmosph ri c deposition of 

lead in dust particles contaminated by 

vehi cl cx hau. t fumes . 

!though mostl y used for agri cultural 

purposes, Dl T also was widely used to 

control mosquitoes in popul ated areas 

until it was banned in 1972. Residual 

concentrations of DDT in urban soil s arc 

a probable source of the relati v ly high 

·onccntrati on of total DDT in streambed 

sediments at site 18 on the Anacostia 

Ri cr (fi g. 7). 

Orchard and Agricultural Nonpoint 

Sources 

Total DDT concentrations in 

streambed ediment exceeded the RL 

value for total DDT at sites 7, 8. and 15 in 

the north-central Great Valley (fi g. 7). 

The. c three site. are ncar and downstream 

from areas where fruit orchard are mo t 

prevalent in the Potomac Ri ver Basin. In 

addition. the areas drained by these three 

sites have . ome of th mo t inten ively 

cropped farml and in the bas in . The past 

usc of DDT to control in ects in orchards 

and on cropl and probabl y is the maj or 

source of the relati vely high total DDT 

concentrations in streambed sediment 

measured at these three sites. 

ENVIRONMENTAL 

IMPLICATIONS OF 

CONTAMINANTS IN 

STREAMBED SEDIMENTS 

The occurrence of lead, mercury, 

chlordane, total DDT, and total PCB' tn 

·trcambcd sediments throughout the 

Potomac Ri ver Bas in ha event! important impli ca tions for stream-ecosys tem 

and human health . Factor · such as the 

environmental persistence of the contaminant , their a ailability for downstream 

transport , their potential for bioaccumul ation in aquatic organi sm , and their possible effect: on human health, are briefl y 

di scussed in the following sccti ns. 

Environmental Persistence 

Once the contaminants arc introduced 

into streambed sediments, they can 

10 Contaminants in Streambed Sediments 

remain there for long period. of time. 

While present, they can be available 

under certain environmental conditions to 

cause adver e effec t on aquati c organism . . An example of the environmental 

per istcnce of contaminant. in the 

Potomac Ri ver Bas in i the occurrence of 

total DDT in streambed sediment at all 

ite sampled during the 1992 survey, two 

decades after the usc of the 1 esticide wa. 

banned in 1972. Another even more compel ling example is the presence of elevated mercury concentrations in streambed 

sediments at ite 12 on the South Ri ver in 

1992. more than four decades after the 

use of mercury was di scontinued in the 

nearby indusu·i al pl ant that released the 

mercury into the environment. The 

occurrence of total PCB's and chlordane 

in streambed sediment at sa mpled ites 

also are examples of the environmental 

per istcnce of contaminants years after 

their use was banned. 

Availability for Downstream 

Transport 

During high streamflow periods, 

streambed sediments are mobili zed and 

transported downstream. onscquentl y, 

the contaminants stored in the sediments 

also arc transported and redeposited in 

lownstrcam reaches of the streams. 

Through thi s frequentl y recurring process, 

contaminants are introduced into new 

area of the stream ecosystem, thereby 

becoming available for ingesti on by 

greater numbers of aquatic organi sms. An 

example of the transport of contaminants 

in ·treambed sediments is the occurrence 

of mercury in the Shenandoah Ri er 

Bas in . As noted earli er, the mercury was 
14.50 

• Figure 8. Several sampling sites with high concentrations of mercury 

in streambed sediments are downstream from a known source of mercury contamination in Waynesboro, Va. 

Organisms that li in the sedim nts 

can ingest the contaminants and 

a umulate th min their li. sues. 

ST 

0 46 

( ) i.!:~ 12 

I HARPE 

}-Potorn 

EXPLANATION 

• Known source of mercury 

\. 

.A. Sites with mercury concentration, in parts per million 

0. 17 

I Proportional bar showing mercury concentration in 

streambed sediments, in parts per million 

STA 

released into the environment along the 

South River in Wayne boro, Ya. (fi g. 8). 

Through decades of down tream transport 

of mercury-c ntaminated ediments, mercury has accumulated in high concentrations in streambed ediments at site 12 on 

the South Ri ver at Harri ton, 16 ri ver 

miles down tream from the indu tri al 

source; at site 13 on the outh Fork 

Shenandoah Ri ver at Front Royal, 11 8 

river miles down tream from the source; 

and at ite 15 on the Shenandoah Ri ver at 

Millvi lle, 171 ri ver mi les downstream 

from the source. oncentration of mercury in streambed ediment at these sites 

decrease with distance downstream from 

the source in Wayne boro, Ya. It al o is 

possible that mercury released along the 

South River has reached the treambed 

sediment at . ite 19 on the Potomac River 

downstream from Wa hington, D.C. 

.£ 

Q) 

c 

0 

"2 

0 

:c 

0 

10 

8 

6 

4 

2 

0 

5 7 11 

The bioa cumulation of the ont·tminants 

in the e aquatic organi. ms has been 

h wn to cause ariou. ph siolooical 

problem and even death r the rganisms 

when contaminant con en trat ions exceed 

ERL and ERM JUid lin s (Long and others. 1995). In addition, these a ·cumulated 

on entrati ons can be passed on to higher 

organi. ms in the food chain as a result 

of the higher organism. ingesting 

contam in·lted oroani sms that li ve 

in the . ediment s. One example 

f the r lati on of streambedsediment contaminati on to 

WAS t li N .T N 1).( ... the resulting contaminati on of higher organisms 

is shown in fi gure 9. As part 

of the 1992 sur y, ti s. u s from 

ca tfl h (yellow bullheads) were collected at eight of the . ite. wher 

treambed sed im nts were collected . 

The correlati n coeffi ·ient ( pearman 's 

rho) between chlordane concentrati ns in 

sed iments and chlordane concentrations in 

catfi sh ti ssues is 0.94, indi cating a strong 

dire t relation between th occurrenc of 

the contaminant in treambed ed iments 

and the presence of the contaminant in 

fish ti s ues. 

140 

120 

100 

.£ 

80 

60 

40 

20 

0 

14 16 17 20 21 

Potential for Bioaccumulation in 

Aquatic Organisms 

Site numbers for sites where both streambed 

sediments and yellow bullhead tissues were sampled. 

The presence of these contaminant 

in streambed sediments can have a signi ficant adverse effect on aquatic organisms. 

Figure 9. Chlordane concentrations in catfish tissues are closely correlated with chlordane concentrations in streambed sediments at eight sampling sites where both media were sampled. 

Contaminants in Streambed Sediment 11 
Possible Effects on Human Health 

Some of the possible effects of the 

contaminant: on human health are documented in tab! 2. One way that human. 

can be exposed to the contaminant. i · 

through the food chain. The human con-

. umption of fish from streams with contaminated ediment and the human conI \IIIII I ~ 1~ ~rn~ l ij li ~~ ~11 l I \Ill 

3 1818 00197652 9 

umption of terre ·tri al animfl l who 1 rey 

on contaminated fi h can lead to the 

bi oaccumulati n of the contaminant in 

human ti ues. Fish surveys conducted in 

the Potomac Ri ver Bas in have detect d 

unacceptable levels of mercury, chlordane, and total P B's in fi sh ti s ue in 

selected tream and. as a result, have 

prompted State regulatory agencie. to 

issue bans or re trictions on the human 

consumption of fi sh from certain 

reache of the stream . 

ACKNOWLEDGMENTS 

PCB contamination in the South Fork 

Shenandoah River has caused contamination 

of fish, resulting in restrictions on human consumption of fish. 

The author are grateful for the valuab le assi tance prov ided by the members 

of the report team: Adrienne emura f 

the M etropolitan Washington Council of 

Government , and John Brakebill. Valerie 

Gaine. Cherie Miller. cott Phillip , and 

Cel. o Puente of the SGS. Al so appreciated is the illustration a sistance provided 

by Willie aughron and Sarah Kelley of 

the USGS, the editorial assistance provided by Sheryl Protan i of the U GS. and 

the photographs provided by David Usher 

of the USGS, and John Batti. ta, a volunteer. Streambed-. ediment ampling assistance wa provided by Bruce Bernard and 

Janet Deni s of the USGS. Finally, 

Willi am Foreman, Edward Furlong, and 

Richard Sanzolone of the USGS are 

acknowledged for their ·upport in the laboratory analysis of ample and the interpretation of analyti cal result ·. 

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Brigg., Pau l, 1990, Elemental analys is of geologica l materi al by inducti vely coupled 

pia ma-atomic emi sion pectrometry, in 

Quality assurance manual for the Branch 

of Geochemi u·y. .S. Geological 

Survey : .S. Geological Survey OpenFi le Report 90-668, 184 p. 

Brooks, K.M ., 1977, Critical areas in the 

Potomac Ri ver Basin, A mid- 1977 

review of water-pollution control: 

Interstate ommi ssion on the Potomac 

Ri ver Basin Technical Publicati on 77-3, 

77 p. 

he apeake Bay Program, 1991 a. Chesapeake 

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En ironmental Protecti on Agency. 9 p. 

__ 199 1 b. Chc,apeakc Bay 10xics of concern li. t information sheets: .S. 

Environmental Protecti on gene . 

11 2 p. 

Foreman, W.T. . Connor. B.F., Furlong. .T.. 

Vaught. D.G., and Leslie. M .M .. 1995. 

Methods of analysi by the .S. 

Geological Survey ational WaterQualit y Laboratory-Determinati on of 

organochlorine pesti cides and polychlorinated biphenyl · in bottom . edimcnt by 

dual capi llary-column gas chromatography with electron-capture detecti on: 

U.S. Geological Survey Open-Fi le 

Report 95- 140, 78 p. 

Fyfe, W. .. 1974, Geochemistry: Oxford 

Uni versit y Press, I 09 p. 

Gilliam, R.J ., Alley, W.M .. and Gurtz, M . . , 

1995, Des ign of the Nati onal WaterQuality Assessment Program: 

Occurrence and distri buti on of waterquality conditions: .S. Geological 

Survey ircular 111 2, 33 p. 

12 Contaminants in Streambed Sediments 

Long. E. R. , M acDonald. D.D., mith, .L.. 

and Calder, F. D., 1995, Incidence of 

adver c biological effect within ranges 

of chemi cal concentrati on. in mari ne 

and e tuarine sedimems: Environmental 

M anagement. v. 19, no. I , p. 1-97. 

Long. E. R. and M organ, L.G., 1990. The 

potent ial for biologica l effect. of sediment-sorbed contam inant tested in the 

ati onal Statu. and Trends Program: 

.S. ational 0 eanic and Atmospheric 

Admini. !rati on. Technical Memo OS 

OMA 52. 175 p. 

O' Leary, R.M .. Crock, J.G., and Kennedy. 

K.R .. 1990, Determination of mercury in 

geologic material by continuous flowcold vapor-atomic absorption spectrophotometry, in Quality a surance 

manual for the Branch of Geochemistry, 

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Geological Survey Open-Fi le Report 90-

668. 184 p. 

.S. En ironmental Protection Agency. 1991 , 

Fact sheet: Nati onal primary dri nking 

water standard ·: .S. En ironmental 

Protecti on Agency, EPA 570/9-9 1-

0 12FS. 8 p. 

Virginia Water ontrol Board. 1992. Virgini a 

water quality assessment for 1992: 

Virginia Water Control Board 

Information Bulletin #58 . v. 2. 444 p. 

Wade, T.L., Velinsky, D.J .. Reinharz. Eli, and 

Schlckat, .E .. 1994, Tidal river sediment · in the Washington. D .. area. II. 

Di tribution and source of organic contaminant. , in Estuari c : tuarine 

Re earch Federation, vol. 17. no. 2. p. 

32 1-333. 

For further information contact: 

District hief 

.. Geologica l Survey 

208 arroll Buildi ng 

8600 LaSalle Road 

Tow on, MD 2 1286 

Internet: in fo srvrdmdtw .er.usgs.go 

WRIR 95-4267