After years of legal wrangling with Fairfax County over its water system, Falls Church is hoping to sell its water utility entirely — for about $44 million. Falls Church officials say that the beleaguered water system has faced so many legal challenges over the past several years that it has become too risky to keep the system under the city’s control. So far they city has heard from 10 potential buyers, including the Fairfax County Water Authority itself. Potential buyers can expect to pay at least $44 million for the system, plus another $30 million in obligations like debts and employee pensions.