Revegetation of a contaminated zinc smelter site

Lund.scapr

and I’rhan

Planning,

17 ( 1989)

Revegetation

241

24 I-250

Elsevier Science Publishers B.V.. .Amsterdam -

Printed in The Netherlands

of a Contaminated

WILLIAM

Zinc Smelter Site

E. SOPPER

(Accepted for publication 4 July I988 )

ABSTRACT

Sopper. W’.E.. 1989. Revegetation qfa contaminated zinc smelter site. Landscape Urban Plann., 17: 241-250.

Over 800 hu of:ftwest vegetation are dead on Blue Mountain ut Palmerton, Pennsylvania The ma.jor cu~~seM’US emissions of Zn, Cd, Cu, Ph. and SO,.fiwm a zinc smelter operating since 1898. In 1985, a research ejfort \vas initiated to develop N remedial action program to mitigate the environmental damage. Field plot studies rtwe conducted to determine the .fkasibilit_v qf using mi.utwe.s of.deM’atered municipul sludge

andflJ> ash as amendments to,fucilitate the establishment qfvegetation on the highl)?contaminated soil. Three mixtures ofsludge (S) und,flJ> ash (FX) tilere evaluated (IS:lFA, 2S:IF.4, und 3S:IFA). The amendments M’ereapplied on 0.4ha plots in May 1985. Five grass and legume seed mixtures were hydroseeded on subplots, fi)r evaluation. In addition, seedlings qf’I0 tree species and hybrid poplar cuttings tt’ereplanted on the plots. After tvi’ogrotiing seasons. results indicate that all three sllrdge7fl~~ash mi.\~tww were sziccessf~d in ,f?icilitating vegetution establishment.

INTRODUCTION In 1900, the north slope of Blue Mountain in the vicinity of Palmerton, Pennsylvania was a densely forested area. Today, over 800 ha are a barren, devastated, biological desert. Approximately 50% of the slope area is strewn with rocks and boulders exposed by severe erosion over the past 50 years which has removed about 30 cm of the original surface soil. The major cause was emissions of Zn, Cd, Cu, Pb, and SO2 from a zinc smelting plant which has been operating in Palmerton since

Ol69-2046/89/$03.50

0 1989 Elsevier Science Publishers B.V.

1898 (Buchauer, 1973). In addition, the area was also subjected to extensive logging and frequent fires (Jordan, 1975). Natural revegetation has been hampered primarily by the high Zn concentrations in the surface mineral soil and organic detritus material present on the area. Soil nutrients have been washed away, microorganism populations are virtually nonexistent, and the surface soils are droughty with extreme variations in microclimate. As a result, the normal balance of vegetation, soil microorganisms, and the recycling of soil nutrients has been severely disrupted by the

accelerating denudation and erosion. The Blue Mountain site represents a unique set of reclamation challenges. First of all, the area is totally inaccessible to vehicles because the slopes are covered by rocks. boulders. and undecomposed tree stems. Access would only bc possible by bulldozing new roads. The slopes are steep averaging 30% and ranging from 25 to 100%. Most vehicles used to spread lime. fertilizer, or sludge must be able to traverse the site. This is not possible on this site, so that it would be necessary to use a spreading vehicle which could apply the amendments aerially considerable distances (30-45 m) onto the slopes. Incorporation of the amendments, a usual practice. would also not be possible on this site. And lastly, the surface soil is highly contaminated with trace metals providing another impediment to vegetation establishment. Background surface soil samples taken downwind approximately at mid-slope on Blue Mountain contained 31 316 ppm of Zn. 5225 ppm of Pb, and 1248 ppm of Cd (Shoener et al.. 1987 ). The normal ranges for uncontaminated soils in the United States are lo-300 ppm for Zn. 2-200 ppm for Pb. and 0.0 l-7.00 ppm for Cd (Allaway, 1968 ). A considerable portion of the area is also covered with a layer of black humus detritus that appears to be undecomposed tree bark. Analyses of this material showed equally high concentrations of trace metals - 29 475 ppm of Zn, 123 I ppm of Cd, and 6237 ppm of Pb. Soil samples taken to a depth of 90 cm indicated that the depth of adverse contamination for Zn ( > 200 ppm) and Cd ( > 5 ppm) ranged from 5 to 30 cm. To my knowledge, reclamation of such a site has never been attempted. In 1982. the area was placed on the National Priorities List and designated as a “Superfund” site by the U.S. Environmental Protection Agency. Under a consent agreement signed 25 September 1985, a Remedial Investigation/Feasibility Study was initiated to find a remedial action program which would mitigate the environmental damage. Cooperating

with the U.S. Environmental Protection Agency were the Department of Public Works, City of Allentown: Pennsylvania Power and Light Company: the Soil Conservation Service, USDA: and the Environmental Resources Research Institute. The Pennsylvania State University (Shoener et al.. 1987 ). It was quite obvious that attempting to plant or direct seed vegetation on the existing soil surface would be futile since natural revegetation had not occurred over the past 50 years. It is not possible for grass. legume. and tree species to germinate and survive when seeded directly on the highly contaminated soil. Thus. it was concluded that some type of growing medium had to be placed on top of the contaminated soil. Some possibilities were top soil, peat-vermiculite potting mixtures. and waste products. Economics eliminated the first two possibilities. So, attention was focused on local waste products. It was decided to investigate sludge and fly ash because of the potentially large volumes that might be needed. The hypothesis being evaluated is to determine if vegetation germination, survival. and growth can be facilitated by using various mixtures of sludge and fly ash as a growing medium on top of the contaminated soil which would provide a nutrient support system for the vegetation until some part of the root system penetrated the highly contaminated surface soil (j-30 cm ) to reach the uncontaminated subsoil. The assumption is that vegetation survival would be greatly enhanced once the roots reached the normal uncontaminated subsoil. Since the sludge could not be incorporated. it did not seem feasible to apply sludge alone. Its poor physical characteristics (wetting and drying), when applied on the soil surface without incorporation. would not be conducive to seed germination. Thus. it was decided to use the fly ash in a mixture with sludge to make a more friable product. Based upon analyses of dewatered digested sludge from the Allentown wastewater treatment plant and fly ash from the Pennsylvania

243

Power and Light Company generating plant, it was decided to evaluate three sludge-fly ash mixtures. The mixture ratios (on volume basis) selected for evaluation were 1S: lFA, 2s: 1FA, and 3s: 1FA. METHOD OF STUDY In May 1986, nine 0.4-ha plots were established along a road bulldozed to provide access to the mid-slope area of Blue Mountain. The plots were located in sets of three for the application of the three sludge-fly ash mixtures. Because of the low potassium content of the sludge, a potassium supplement equivalent to 90 kg ha-’ was applied to the plots with the lime. Lime was applied at 22 Mg ha-’ which was double the amount required to raise pH to 7.0 based on a soil analysis. The lime was applied at this higher rate because of the extremely high concentrations of trace metals in the black humus detritus material that sporadically covers large areas. The lime and potash were applied to the plots using an Estes “Aerospreader” truck. The application rates for the sludge-fly ash mixtures were determined on the basis of previous research results using sludge to revegetate barren strip mine land. From that research it was found that successful vegetation establishment was assured if the sludge was applied at a rate sufticient to supply a minimum of I 120 kg of total nitrogen ha-‘. Because of the high N concentration in the Allentown sludge, only about 22 Mg ha-’ would have to be applied to supply 1120 kg N ha-‘. However, this amount would not provide sufficient depth of growing medium to support vegetation. Therefore. it was decided to double the application rate. This application rate would create a large enough pool of nutrients (N and P) to sustain vegetation growth for at least 3-5 years. Typical chemical analyses of the sludge and fly ash used in this project are given in Table 1. These are the average values for several composite samples collected as the products

were unloaded at the storage area at the base of Blue Mountain. The two amendments were mixed at the storage area with a front-end loader and applied to the plots with an Estes “Aerospreader” truck (Fig. 1). The amounts of chemical constituents applied with each mixture are given in Table 2. These values were calculated from analyses of samples collected during application of the mixtures to the plots. The amounts of trace metals applied in all mixtures were well below the allowable maximum amounts recommended by the Pennsylvania Department of Environmental Resources (PDER) for mine land reclamation (Table 2 ). Each field plot was subdivided into 5 subplots for hydroseeding of five different TABLE I Typical chemical analyses of the sludge and fly ash used in this project Constituent

PH

Sludge concentration 8.3

% Total P

1.06

Total N NH,-N Org-N Ca Mg Na K Al Fe B

3.59 0.45

3.14 5.10 0.35 0.12 0.23 1.99 2.94

Fly ash concentration 8.9

MK’ 70

5240 72

88 211 23 ‘5 I3

Pgg-’ Mn Zn CU Pb Cr Ni Cd Hg Solids (%) Soluble salts

839 I763 147 I54 379 94 I.4 23

2.5 I5 3.8 I.2 43 0.3 0.’

I. .Applicatlons of llmc and the various “~erospreadcr” truck

sludge-O>

ash amendment

seed mixtures. Seeding mixtures were: ( I ) Blackwell switchgrass (Punicxm virgutllm ) ( 17 kg ha- ’ ) or cave-in-rock switchgrass (Put?;cl(m vir;yutfzlm) ( 17 kg ha-’ ): (2 ) Niagara big bluestem (.~ndropogorr gerurdi) ( 34 kg ha-’ ); ( 3 ) Empire birdsfoot trefoil ( LO~ZLScorniczrlu/l/.\) (22 kg ha- ’ ); and Ky-3 1 tall fescue (FesIMN untndinuwuc) (45 kg ha- ’ ): (4) Pennfine perennial ryegrass (I~Aizlm pcrennc) (22 kg ha- ’ ) and Lathco flatpea (La~h~ms .~~‘hc~.s~ri.s) (67 kg ha-’ ): (5) Oahe intermediate wheatgrass (.4grop~wm inkrmedium ) ( 34 kg ha- ’ ). In mid-summer. three subplots originally seeded with cave-in-rock switchgrass were reseeded with the mixture of Ky-3 1 tall fescue ( F~~.SIUCYI urlrndinuwuc) ( 22 kg ha- ’ ), orchardgrass (fIAx~r~~1i.s~~lomeruru ) (22 kg ha- ’ ) and Penngift crownvetch (Cbronillu vuriu) ( 17 kg ha-’ ). All field plots were mulched with Iiher mulch at an approximate rate of 2240 kg

mixtures

were applied

to the field plots with an Estes

ha- ‘. Mulch was applied with a hydroseeder. Ten species of tree seedlings were then planted on the field plots during the period 25 June 1986. Tree seedling survival rates in 1986 were poor due to the late planting date and the fact that many seedlings dessicated while being held in storage for 2 months. In 1987. tree seedlings were again planted on the field plots. Species planted were white pine ( Pinlls .slwbus), Austrian pine (Pinus nigru ) , Virginia pine (Pinzss virginiana ), red pine (Pinus rrsinosa ), Japanese larch ( Lark Icytolq.cis), black locust (Robiniu pselldoucuciu ). Arnot bristly locust ( Rohiniu jiwiiis), European alder (Alnzo gfutinosa ) , black cherry ( Przrnza serotinu ), sugar maple (Accv .rucAmun ), and hybrid poplar (Popzhc spp. ) cuttings. Seven seedlings of each species except hybrid poplar were planted on each field plot. Ten cuttings of hybrid poplar were planted on each plot.

245 TABLE

2

TABLE 3

Sludge-fly ash mixture applicatton chemical constituents applied ha-’

rates

Constituent

applied

and

amounts

of

Average percentage Seed mixture

PDER maximum limits

Total P Total N NH,-N Org-N Ca Mg Na K .4l FC Mn Zn cu Pb Cr Ni Cd Hg

224 II2 II2 112 22 3

Amount

vegetation Subplot

cover

Amendment

mixture

1987

1986

(kg haa’)

IS:I FA 2s: I FA 3s: I FA IS:IFA’

‘S:IFA-‘

3S:lFA’

1214 2455 282 2172 5419 620 197 1157 9878 I0131 43 100 68 26 46 22 0.9 0.1

II20 3030 297 2733 5466 626 I48 560 4791 6635 464 109 83 19 39 18 0.9 0.1

991 2735 314 2421 3563 326 101 401 3700 3939 26 59 53 16 34 IO 0.8 0.1

‘47 dtSz235 dtFA; 235 wtS=235 dtFA. ‘47 dtS= I 17.6 dtFA; 235 wtS= 117.6dtFA. ‘47 dtS= 78 dtFA; 235 wtS= 78 dtFA.

RESULTS AND DISCUSSION Herbaceous vegetation growth responses At the end of each growth season in 1986 and 1987, growth responses of the various grass and legume seeding mixtures were evaluated. Visual estimates of percentage cover were made using a 0.25-m’ frame laid on the soil surface at 6-m intervals along two transect lines 3 m apart in the center of each subplot. A total of ten estimates were made subplot-‘. The average percentage cover for each seeding mixture is given in Table 3. Of the five original seed mixtures, the highest percentage vegetation cover (8 1o/o) was obtained with the birdsfoot trefoil and tall fescue mixture and the pennfine perennial ryegrass and lathco flatpea mixture. The highest percentage covers were observed on the 1S: 1FA and 2s: 1FA. The mixture of orchardgrass, tall fescue, and crownvetch, se-

Blackwell switchgrass’

1

9s4

19

Cave-in-rock switchgrass’

I

-

-

Niagara btg bluestem

2

53

Btrdsfoot trefotl and tall fescue

3

Penntine perennial ryegrass and Lathco flatpea

-

59

40

2

2


39

32

41

21

95

98

49

81

74

4

73

88

81

81

46

Oahe intermediate wheatgrass

5

23

45

12

27

I6

Orchardgrass, tall fescue and crownvetch3

I

91

90

97

93

90

‘Seeded on Field Plots 2.4. and 6. ‘Seeded on Field Plots 3. 5, 7. and 9. ‘Overseeded on Subplot I on Field Plots 3. 5, and 9 in July 1986. ‘Mostly invading volunteer vegetation.

lected on the basis of its successful use on sludge reclaimed mine land, overseeded on the cave-in-rock switchgrass subplots produced the highest percentage cover of all mixtures evaluated. In 1986, this seed mixture had an average cover of 90% and ranged from 82 to 95% among the three sludge-fly ash amendments. In 1987, average cover increased to 93%. The average percentage covers for all seed mixtures were higher in 1987 than in 1986. No measurements of dry matter production were made in 1986 because deer browse on the plots was so heavy it made taking yield samples virtually impossible. However, in July 1987, yield samples were collected by harvesting all vegetation within a 30 by 30 cm square frame placed on the soil surface at 7.5-m inter-

236

vals on a transect line in the center of each subplot. Three samples subplot-’ were collected (Table 4 ). The highest dry matter production (5761 kg ha-’ ) was produced by the orchardgrass, tall fescue and crownvetch mixture. Three of the highest average yields were measured on the 2s: 1FA amended plots. Foliar samples of all seeded species were collected in August 1987, for analyses of nutrients and trace metals. Nutrient concentrations were quite adequate for optimum growth. For the grass species, foliar N concentrations ranged from I .55 to 3.97%. foliar P ranged from 0.1 1 to 0.44O/o, and foliar K ranged from 1.15 to 3.65% across all amendments. Foliar concentrations of P and K in the legume species were similar: however. N concentrations were generally higher. Foliar concentrations of Cu, B. TABLE

4

Average dry matter turc in I987 Seed mtvture

production

Subplot

(kg ha

Xmendment

’ ) for each seed mix-

mixture

Average

lS:lF4

2S:IF.-\

3S:lFA

_

Blackwell swttchgrass

I

4410

2432

(‘a\ c-In-rock swttchgrass

I

_

_

Ntagara big bluestem

2

1932

1648

I908

I829

Birdsfoot trcfotl and tall fescue

3

5260

6201

3166

4876

3421

83

83

Pcnnfine perennial ryegrass and Lathco flatpca

4

3076

6469

3931

4492

Oahc rntcrmedtate whcatgrass

5

5144

2883

995

3007

Orchardgrass, tall fescue and crownvetch’

I

4982

7454

4848

5761

‘Overseeded

on Subplot

1 on Field Plots 3. 5, and 9.

and Ni were all below the suggested tolerance level in all species on all three amendment mixtures except for B in birdsfoot trefoil on the 1S: 1FA mixture (Table 5 ). The tolerance levels show are not phytotoxic levels but suggest foliar concentration levels at which one may expect decreases in growth (Melsted, 1973: Adriano, 1986). Foliar Zn, Cd, and Pb concentrations exceeded the tolerance level in all species on all three amendment mixtures except for Cd in ryegrass on the 3s: I FA mixture. Highest Zn concentrations were found in ryegrass, big bluestem, and orchardgrass. Big bluestem also had the highest foliar Pb concentrations. Tall fescue had the highest foliar Cd concentrations. Foliar Mn concentrations exceeded the tolerance level in crownvetch and Lathco flatpea on all amendments. whereas concentrations in birdsfoot trefoil were lower than the tolerance level on all amendments. All grass species had foliar Mn concentrations under the tolerance level except for ryegrass on all amendments, tall fescue on the 2s: 1FA amendment and orchardgrass on the IS: 1FA and 3s: 1FA amendments. No phytotoxicity symptoms were observed on any species. A comparison of 1986 and 1987 foliar analyses results indicated that concentrations of B, Cu. and Pb generally increased in all grass and legume species and Mn, Zn, Cd, and Ni generally decreased. Concentrations of Ni were variable, generally increasing in the legumes and decreasing in the grasses.

Survival counts and height growth measurements were made on 10 September 1987. The highest rate of survival (800/o) for all species was found on the 2s: 1FA amendment (Table 6 ). Species survival ranged from a low of 44O/o for Virginia pine to 91% for European alder. Species with the highest survival rates across all amendments were alder (9 1(/o). black locust (86O/o), black cherry (84Oh ), white pine (83%), larch (810/o), and hybrid poplar (77%).

247 TABLE 5 Foliar trace metal concentrations

(pg gg’ ) herbaceous species

Species

Amendment mixture

Mn

Blackwell switchgrass

lS:IFA 2S:lFA 3S:IFA IS:IFA 2s: I FA 3S:lFA lS:lFA 2s: I FA 3S:IFA IS:IFA 2S:lFA 3S:IF.4 IS:IFA 2S:IFA 3s: I FA lS:IFA 2s: I FA 3s: I FA IS:IFA 2S:lFA 3S:lFA lS:lFA 2s: I FA 3S:IFA 1S:IFA 2s: I FA 3S:IFA IS:IFA’

108 II 189 22 (no sample) (no sample) I35 I8 35 8 85 30 98 15 92 I3 101 16 379 28 161 20 333 29 632 36 499 29 94 14 I68 25 92 13 331 36 I25 I8 360 54 375 40 694 63 438 55 295 128 250 94 216 79 392 81

Cave-in-rock switchgrass

Niagara big bluestem

Tall fescue

Ryegrass

Wheatgrass

Orchardgrass

Lathco flatpea

Btrdsfoot trefoil

Crownvetch Tolerance level’

300

B

cu

100

Zn

Pb

Cd

Ni 2 3

16 18

576 715

30 83

4 5

25 I4 27 22 37 I7 24 25 50 36 46 24 21 27 20 26 30 48 45 41 34 36 35 24

961 491 1066 1089 808 721 950 762 II15 1396 804 605 470 451 550 1582 474 979 2082 1080 666 1121 588 1356

II3 76 87 II8 51 49 69 43 60 51 87 75 38 60 57 98 64 63 87 56 56 59 56 62

8 6 11 7 16 20 20 21 I5 17 I I4 8 9 7 I7 5 14 I7 I2 I1 26 I6 I8

I50

300

10

3

8 I4 20 16 3 3 3 9 9 16 12 II II 12 11 13 50

‘No plants available to sample on the 2s: I FA and 3s: I FA. ‘Foliar concentration level at which one may expect decreases in growth.

TABLE 6

TABLE 7

Tree seedling survival (%)

Tree seeding height growth (cm)

Species

IS:IFA

2S:IFA

3S:IFA

All treatments

Species

IS:lFA

2S:lFA

3S:IFA

All treatments

White pine ‘Austrian pine Virginia pine Red pine Larch Black locust ,Arnot bristly IOUust Alder Black cherry Sugar maple Hybrid poplar

86 79 50 36 86 93 64 72 93 79 100

79 93 50 79 79 100 79 100 72 72 75

86 57 33 57 79 65 65 100 86 79 55

83 76 44 57 81 86 69 91 84 77 77

White pine Austrian pine Virginia pine Red pine Larch Black locust Arnot bristly locust Alder Black cherry Sugar maple Hybrid poplar

I9 24 14 17 34 55 46 59 52 34 34

I5 I7 18 19 28 49 35 53 57 39 21

I9 20 21 17 58 39 46 46 61 38 52

18 20 I7 17 40 47 42 52 57 37 38

76

80

69

All species

35

32

38

All species

Fig. 3. Gcncral biew of herbaceous vegetation months after amendment application.

and alder tree seedlings

on a field plot at the end of the 1987 growing

season,

I5

249 TABLE 8 Effects of sludge-fly ash amendments

on selected trace metal concentrations

Tree species

Amendment mixture

Mn

White pine

IS:lF.4 2S:lFA 3S:IFA IS:lFrZ 2% I E4 3S:IFA IS:IFA 2% I FA 3s: I F.4 1S:lF.A 2s: I FA 3s: I F.4 IS:IFA 2% I FA 3S:lF.A IS:lFA 2s: I F.A 3s: I F.A

947 791 732 103 170 I59 103 I68 I21 I54 441 I64 I21 215 170 I06 179 89 300

Larch

Black locust

Alder

Black cherry

Hybrid poplar

Suggested tolerance level’ ‘Foliar concentration

cu

(,ugg- ’ ) in the foliage of tree seedlings

B

Zn

Pb

Cd

Ni

14 I3 I3 7 8 7 I2 12 I2 25 20 21 I2 II 9 9 IO IO

56 47 33 66 84 71 I04 81 72 57 58 56 29 34 28 64 34 47

700 840 604 408 402 450 870 430 470 1258 807 2070 1033 887 490 1605 1650 4000

40 31 49 34 33 42 88 59 47 I40 104 76 99 84 53 34 70 28

I4 6 I4 6 5 4 II 7 I2 5 4 3 7 6 4 32 27 66

4 4 4 3 3 3 6 6 6 7 7 IO 5 3 4 3 4 4

150

100

300

IO

3

50

level at which one may expect decreases in growth.

There was little difference in average height growth within a species among the three amendments (Table 7). Larch had the best height growth (40 cm ) of the coniferous species and black cherry had the best height growth (57 cm) of the hardwood species. The two species which exhibited the most vigorous growth were larch and alder. A genera1 view of a portion of the devastated mountain slope is shown in Fig. 2 and a general view of the herbaceous vegetation and some alder seedlings at the same location, 15 months after the amendments were applied (Fig. 3 ). Foliar samples were collected on 10 September 1987 from all tree species and analyzed for nutrients (N-P-K), cations (Ca and Mg), and trace metals (Mn, Fe, Al, B, Cu, Zn, Pb, Cd, Ni, Co, and Cr). Nitrogen concentrations in the coniferous species ranged from 1.OO to 1.70% and in the hardwood species from 1.34 to 3.34O/o across all amendments. In general, the hardwood species had higher concentrations of nutrients and cations than the coniferous spe-

ties. Within a species, there was little difference in nutrient and cation concentrations among the three amendment mixtures. Results of the foliar analyses for trace metal concentrations are given in Table 8. Due to limited space, data are presented only for the potentially most toxic elements and selected species. Foliar concentrations of Cu, Ni, Cr. and Co were under the suggested tolerance level for all tree species on all amendments. Similarly, foliar B concentrations were all below the suggested tolerance level for all tree species on all amendments except for black locust on the 1S: 1FA mixture. Foliar Mn concentrations were all below the suggested tolerance level except for white pine on all three amendments and alder on the 2s: 1FA mixture. Foliar Pb concentrations exceeded the suggested tolerance level in all species on all amendments. The highest foliar Pb concentration was 140 mg kgg’ in alder. Foliar Cd concentrations equalled or exceeded the suggested tolerance level in all species on all amendments. Hybrid

250

poplar had the highest Zn and Cd concentrations. Alder and black cherry had the lowest Cd concentrations and larch had the lowest Zn concentrations. In general. within a species there was little difference in foliar trace metal concentrations among the three amendments. No phytotoxicity symptoms were observed on any species. CONCLUSIONS On the basis of the vegetation growth responses over a two-year period, it can be concluded that all three sludge-fly ash amendment mixtures were successful in facilitating vegetation establishment on the contaminated soil. Average percentage herbaceous vegetation cover and dry matter production were the highest on the 2s: 1FA mixture. The seed mixture consisting of orchardgrass, tall fescue. and crownvetch exhibited the best growth. Average tree seedling survival ranged from 44 to 9 1O/o across all amendments. with the highest average survival rate ( XOO/o)for all species combined found on the 2s: 1FA mixture. Larch and European alder exhibited the most vigorous growth. Foliar concentrations of Zn, Cd, Pb. and Mn exceeded tolerance levels for growth reduction in almost all grass. legume. and tree species on all amendment mixtures. However. no phytotoxicity symptoms were observed. The establishment of a herbaceous vegetative cover w/ill help to stabilize the slopes and reduce the amount of erosion and surface run-off that continually carry trace metal contaminants into the Lehigh River. The herbaceous cover will provide the needed immediate protection while a permanent forest cover develops on the mountain slope. Plans are now being formulated to continue applying the amendments on

the entire 800 ha on the north slope of Blue Mountain. It is estimated that it will take five years to complete the project. When completed. the entire mountain should again be clothed in a forest cover greatly improving the esthetics of the entire valley. An economic analysis of the cost of applying the sludge and fly ash waste products on the mountain as amendments indicated that it was less costly than usual disposal in landfills. ACKNOWLEDGEMENT Although the research described in this article has been funded wholly by the U.S. Environmental Protection Agency. Region III, it has not been subjected to Agency review and therefore does not necessarily reflect the view of the Agency and no official endorsement should be inferred. The Pennsylvania Bureau of Forestry supplied the tree seedlings for this project. REFERENCES Adriano. D.C.. 1986. Tract Elements in the Terrestrial Environment. Springer. New York. NY. 533 pp. Allawaq. W.H.. 1968. .Agronomic controls over the en\ ironmental cycling of trace metals. 4dv. Agron.. 20: 335-17 I Buchauer. M.J.. 1973. Contamination of soil and vegctatton near a zinc smelter b) zinc. copper. and lead. Environ. Sci. Technol.. 7: 131-135. Jordan. M.J.. 1975. Effects of zinc-smelter emissions and tire on a chestnut-oak woodland. Ecology, 56: 78-9 I Melstcd. S.W., 1973. Soil-plant relationships. In: Recycling Muntcipal Sludge and Effluents on Land. National .Assoc. of State Ltnibersities and Land Grant Colleges. Washington. DC, pp. 111-128. Shoener, E.. Sopper. W.E.. Oyler. J. and McMahon. J., 1987. Palmerton Zinc Superfund Site. Blue Mountain Project. (IS. Environmental Protection Agency, Region III, Philadelphia. PA. Z I5 pp.