Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 15, 2013	Jun. 16, 2012	Jun. 15, 2013	Jun. 16, 2012	Dec. 29, 2012
Segment Reporting Information [Line Items]
Product Revenues	$ 28,906	$ 31,941	$ 55,464	$ 53,157
Service Revenues	34,644	30,330	68,093	59,623
Total revenues	63,550	62,271	123,557	112,780
Operating Costs	52,201	51,908	104,487	94,245
Operating depreciation and amortization	1,903	1,767	3,598	3,402
Profit Before Corporate Selling General and Administrative Expenses	9,446	8,596	15,472	15,133
Selling, general, and administrative expenses	7,049	6,237	13,640	11,994
Depreciation and amortization from SG&A	260	144	424	281
Total selling, general, and administrative expenses	7,309	6,381	14,064	12,275
Other expense (income) - net	101	(2)	93	(2)
Operating income (loss)	2,036	2,217	1,315	2,860
Income before income taxes	1,929	2,071	1,102	2,527
Provision for income taxes	872	853	465	1,039
Net (loss) income			591	1,488
Total Assets	204,555		204,555		199,111
Environmental Services Segment [Member]
Segment Reporting Information [Line Items]
Entity-Wide Revenue, Major Customer, Percentage	10.00%	10.00%	10.00%	10.00%
Product Revenues	2,853	2,832	5,523	5,175
Service Revenues	32,980	29,215	65,101	57,385
Total revenues	35,833	32,047	70,624	62,560
Operating Costs	24,792	23,769	50,340	48,068
Operating depreciation and amortization	1,079	1,079	2,160	2,111
Profit Before Corporate Selling General and Administrative Expenses	9,962	7,199	18,124	12,381
Total Assets	64,019		64,019		57,092
Oil Business Segment [Member]
Segment Reporting Information [Line Items]
Entity-Wide Revenue, Major Customer, Percentage	10.00%	10.00%	10.00%	10.20%
Product Revenues	26,053	29,109	49,941	47,982
Service Revenues	1,664	1,115	2,992	2,238
Total revenues	27,717	30,224	52,933	50,220
Operating Costs	27,409	28,139	54,147	46,177
Operating depreciation and amortization	824	688	1,438	1,291
Profit Before Corporate Selling General and Administrative Expenses	(516)	1,397	(2,652)	2,752
Total Assets	93,017		93,017		87,222
Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Selling, general, and administrative expenses	7,049	6,237	13,640	11,994
Depreciation and amortization from SG&A	260	144	424	281
Total selling, general, and administrative expenses	7,309	6,381	14,064	12,275
Other expense (income) - net	(101)	(2)
Interest expense – net	107	146	213	333
Total Assets	$ 47,519		$ 47,519		$ 54,797