ASSET RETIREMENT OBLIGATIONS (Details 1) - USD ($)	9 Months Ended	12 Months Ended
	Apr. 30, 2016	Jul. 31, 2015
Schedule Of Change In Asset Retirement Obligation [Line Items]
Undiscounted amount of estimated cash flows	$ 6,650,255	$ 6,600,868
Minimum [Member]
Schedule Of Change In Asset Retirement Obligation [Line Items]
Payable in years	2 years 1 month 6 days	2 years 6 months
Inflation rate	0.90%	2.02%
Discount rate	5.15%	6.56%
Maximum [Member]
Schedule Of Change In Asset Retirement Obligation [Line Items]
Payable in years	15 years	15 years
Inflation rate	2.25%	2.25%
Discount rate	8.00%	8.00%