SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Part 4 (Details) - USD ($)				12 Months Ended
	May 04, 2021	May 06, 2020	May 08, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2021
Stock Compensation Plans [Abstract]
Granted (in shares)				0	0	0
Compensation expenses				$ 193,000	$ 178,000	$ 181,000
Unrecognized expense related to non-vested awards of restricted shares granted				68,000
Accounts Receivable [Abstract]
Increase (decrease) in reserve for bad debt					500,000		$ (300,000)
Expense related to allowance for doubtful accounts				100,000	200,000
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable				9,292,000	11,024,000
Less allowance for doubtful accounts				429,000	862,000
Total Accounts Receivable				8,863,000	10,162,000
Summary of allowance for doubtful accounts [Abstract]
Beginning balance				862,000	264,000
Allowance adjustments				(236,000)	754,000
Recoveries				25,000	13,000
Write off of uncollectible accounts				(222,000)	(169,000)
Ending balance				$ 429,000	862,000	264,000
Cash and Cash Equivalents [Abstract]
Maximum maturity period of temporary cash investments considered as cash equivalents				3 months
Restricted Stock [Member]
Stock Compensation Plans [Abstract]
Compensation expenses				$ 193,000	178,000	$ 181,000
Customer accounts receivable - water [Member]
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable				5,986,000	6,707,000
Customer accounts receivable - wastewater [Member]
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable				1,326,000	1,717,000
Miscellaneous accounts receivable [Member]
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable				698,000	699,000
Developer receivable [Member]
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable				$ 1,282,000	$ 1,901,000
Class A Stock [Member] | Restricted Stock [Member]
Stock Compensation Plans [Abstract]
Granted, restricted stock awards (in shares)	5,000	5,000	5,000
Fair market value (in dollars per share)	$ 40.11	$ 35.01	$ 36.11