Property, plant and equipment and construction in progress (Tables)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment [Table Text Block]

	December 31,
	2017		2016
Land	$	3,435,361	$	3,570,361
Buildings		20,135,753		19,366,123
Plant and equipment		61,437,751		62,227,399
Distribution system		33,986,305		33,482,674
Office furniture, fixtures and equipment		3,425,992		3,405,633
Vehicles		1,446,468		1,396,886
Leasehold improvements		261,148		261,147
Lab equipment		158,637		151,233
		124,287,415		123,861,456
Less accumulated depreciation		73,762,351		70,777,351
Property, plant and equipment, net	$	50,525,064	$	53,084,105
Construction in progress	$	1,823,284	$	885,494