1. The plaintiff's claim is dismissed.

2. Of the litigation costs, 70% is assessed against the Plaintiff, and the remainder is assessed against the Defendant, respectively.

1. Basic facts

A. Of the buildings listed in the attached Table 1 (hereinafter “instant building”), the Plaintiff manages the instant building by partitioned ownership of 6/10 of the 1st and 10th and upper floors above the ground (564.81/100 shares), and the Defendant uses the instant building as a transformation station by partitioned ownership of part of the 7th and upper floors above the ground (435.19/100 shares) among the instant buildings.

B. Since acquiring co-ownership of the instant building around April 2004, the Plaintiff, while actually managing the instant building, has collected management expenses, including water rates from the sectional owners.

C. The director of the Seoul Southern Waterworks Business: (a) imposed the Plaintiff the water rate for the entire building of this case; and (b) the Defendant paid the amount claimed by the Plaintiff as the water rate from January 2009 to September 2016.

Water charges consisting of (1) water charges, (2) water charges, and (3) water use charges. Water supply charges, sewerage charges, and water use charges (hereinafter referred to as "water supply and sewerage charges") shall be imposed in proportion to the volume of water used, and water treatment charges for underground water shall be imposed in proportion to the volume of water used.

[Ground of recognition] Facts without dispute, Gap evidence Nos. 2 through 4, the purport of the whole pleadings

2. The assertion and judgment

A. The plaintiff's assertion that the defendant uses the whole underground part of the building of this case separately, and is obliged to bear all the charges for treating leaked groundwater related to the building of this case. However, from January 2009 to September 2016, the defendant's disposal fees are paid in proportion to the ratio of the whole oil area (43.52%) among the building of this case to September 2016, and the remainder is paid on behalf of the plaintiff. Thus, the defendant is obliged to pay the plaintiff a total of 39,821,467 won and damages for delay calculated as shown in attached Table 2 with unjust enrichment.

B. The Plaintiff is fully responsible for the Defendant’s disposal of leaked groundwater related to the instant building.