OPERATING SEGMENTS (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 item	Sep. 30, 2011	Dec. 31, 2011
OPERATING SEGMENTS
Number of reportable segments			2
OPERATING SEGMENTS
Revenue	$ 45,739,000	$ 39,670,000	$ 118,732,000	$ 113,350,000
Direct operating costs	19,893,000	18,810,000	56,164,000	54,825,000
Transportation costs	7,257,000	5,571,000	14,577,000	20,689,000
Gross profit	18,589,000	15,289,000	47,991,000	37,836,000
Selling, general and administrative expenses	6,196,000	5,722,000	18,167,000	15,874,000
Operating income	12,393,000	9,567,000	29,824,000	21,962,000
Interest income (expense), net	(227,000)	(389,000)	(646,000)	(1,256,000)
Foreign currency gain (loss)	1,605,000	(3,661,000)	1,775,000	(2,193,000)
Other	70,000	73,000	672,000	245,000
Income before income taxes	13,841,000	5,590,000	31,625,000	18,758,000
Income tax expense	5,179,000	1,864,000	12,078,000	7,087,000
Net income	8,662,000	3,726,000	19,547,000	11,671,000
Depreciation, amortization & accretion	4,148,000	4,285,000	12,336,000	11,957,000
Capital expenditures	6,690,000	1,819,000	12,433,000	7,493,000
Total assets	223,730,000	203,939,000	223,730,000	203,939,000	202,588,000
Treatment and disposal
OPERATING SEGMENTS
Revenue	38,583,000	34,564,000	104,502,000	94,130,000
Transportation services
OPERATING SEGMENTS
Revenue	7,156,000	5,106,000	14,230,000	19,220,000
Operating Disposal Facilities
OPERATING SEGMENTS
Revenue	45,734,000	39,664,000	118,716,000	113,333,000
Direct operating costs	19,838,000	18,752,000	55,997,000	54,653,000
Transportation costs	7,257,000	5,571,000	14,576,000	20,689,000
Gross profit	18,639,000	15,341,000	48,143,000	37,991,000
Selling, general and administrative expenses	2,868,000	2,925,000	8,310,000	7,757,000
Operating income	15,771,000	12,416,000	39,833,000	30,234,000
Interest income (expense), net	4,000	6,000	13,000	19,000
Foreign currency gain (loss)	(165,000)	218,000	(247,000)	125,000
Other	68,000	73,000	669,000	244,000
Income before income taxes	15,678,000	12,713,000	40,268,000	30,622,000
Net income	15,678,000	12,713,000	40,268,000	30,622,000
Depreciation, amortization & accretion	4,083,000	4,217,000	12,142,000	11,757,000
Capital expenditures	6,690,000	1,773,000	12,400,000	7,369,000
Total assets	215,786,000	194,961,000	215,786,000	194,961,000
Operating Disposal Facilities | Treatment and disposal
OPERATING SEGMENTS
Revenue	38,578,000	34,558,000	104,486,000	94,113,000
Operating Disposal Facilities | Transportation services
OPERATING SEGMENTS
Revenue	7,156,000	5,106,000	14,230,000	19,220,000
Non-Operating Disposal Facilities
OPERATING SEGMENTS
Revenue	5,000	6,000	16,000	17,000
Direct operating costs	55,000	58,000	167,000	172,000
Transportation costs			1,000
Gross profit	(50,000)	(52,000)	(152,000)	(155,000)
Operating income	(50,000)	(52,000)	(152,000)	(155,000)
Other	2,000		3,000	1,000
Income before income taxes	(48,000)	(52,000)	(149,000)	(154,000)
Net income	(48,000)	(52,000)	(149,000)	(154,000)
Depreciation, amortization & accretion	54,000	55,000	162,000	164,000
Capital expenditures			17,000	12,000
Total assets	97,000	91,000	97,000	91,000
Non-Operating Disposal Facilities | Treatment and disposal
OPERATING SEGMENTS
Revenue	5,000	6,000	16,000	17,000
Corporate
OPERATING SEGMENTS
Selling, general and administrative expenses	3,328,000	2,797,000	9,857,000	8,117,000
Operating income	(3,328,000)	(2,797,000)	(9,857,000)	(8,117,000)
Interest income (expense), net	(231,000)	(395,000)	(659,000)	(1,275,000)
Foreign currency gain (loss)	1,770,000	(3,879,000)	2,022,000	(2,318,000)
Income before income taxes	(1,789,000)	(7,071,000)	(8,494,000)	(11,710,000)
Income tax expense	5,179,000	1,864,000	12,078,000	7,087,000
Net income	(6,968,000)	(8,935,000)	(20,572,000)	(18,797,000)
Depreciation, amortization & accretion	11,000	13,000	32,000	36,000
Capital expenditures		46,000	16,000	112,000
Total assets	$ 7,847,000	$ 8,887,000	$ 7,847,000	$ 8,887,000