DISAGGREGATION OF REVENUE (Details) - USD ($)	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	$ 43,342,934	$ 24,553,338
Revenue from completed contracts	5,771,205	7,994,265
Total revenue from contracts	49,114,139	32,547,603
Earned over time
Disaggregation of Revenue [Line Items]
Total revenue from contracts	48,847,110	32,306,643
Earned at point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts	267,029	240,960
Lump sum contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	7,336,710	10,656,189
Revenue from completed contracts	879,978	1,996,247
Unit price contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	29,422,211	8,399,921
Revenue from completed contracts	2,864,049	5,348,660
Cost plus and T&M contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	6,584,013	5,497,228
Revenue from completed contracts	2,027,178	649,358
Petroleum and Gas
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	28,138,467	8,503,489
Revenue from completed contracts	2,899,185	4,280,732
Total revenue from contracts	31,037,652	12,784,221
Petroleum and Gas | Earned over time
Disaggregation of Revenue [Line Items]
Total revenue from contracts	31,037,652	12,784,221
Petroleum and Gas | Earned at point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts	0	0
Petroleum and Gas | Lump sum contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	0	0
Revenue from completed contracts	0	0
Petroleum and Gas | Unit price contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	26,350,168	6,704,069
Revenue from completed contracts	2,465,135	3,631,374
Petroleum and Gas | Cost plus and T&M contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	1,788,299	1,799,420
Revenue from completed contracts	434,050	649,358
Water, Sewer and Other
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	3,319,078	1,724,825
Revenue from completed contracts	408,756	900,549
Total revenue from contracts	3,727,834	2,625,374
Water, Sewer and Other | Earned over time
Disaggregation of Revenue [Line Items]
Total revenue from contracts	3,727,834	2,625,374
Water, Sewer and Other | Earned at point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts	0	0
Water, Sewer and Other | Lump sum contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	0	0
Revenue from completed contracts	0	0
Water, Sewer and Other | Unit price contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	3,072,043	1,695,852
Revenue from completed contracts	398,914	900,549
Water, Sewer and Other | Cost plus and T&M contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	247,035	28,973
Revenue from completed contracts	9,842	0
Electrical and Mechanical
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	11,885,389	14,325,024
Revenue from completed contracts	2,463,264	2,812,984
Total revenue from contracts	14,348,653	17,138,008
Electrical and Mechanical | Earned over time
Disaggregation of Revenue [Line Items]
Total revenue from contracts	14,081,624	16,897,048
Electrical and Mechanical | Earned at point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts	267,029	240,960
Electrical and Mechanical | Lump sum contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	7,336,710	10,656,189
Revenue from completed contracts	879,978	1,996,247
Electrical and Mechanical | Unit price contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	0	0
Revenue from completed contracts	0	816,737
Electrical and Mechanical | Cost plus and T&M contracts
Disaggregation of Revenue [Line Items]
Revenue from contracts in progress	4,548,679	3,668,835
Revenue from completed contracts	$ 1,583,286	$ 0