Resolving contamination issues with the quagga mussel, a small invasive shellfish, could make the difference between a slightly balanced budget and one that is seriously in the red for Central Basin Municipal Water District. The approximate $50.7 million budget, approved Monday by the Board of Directors, projects $1.7 million in revenue coming from selling water to the Water Replenishment District of Southern California. Only right now, there’s no way to get water to the WRD because Los Angeles County won’t allow Central Basin’s supplier, the Metropolitan Water District, to deliver because of the contamination issues.