Subpart 5. Tax Exemptions; Legal Investment; Water Pollution; Reservoirs; Metro Contributions; and Revenue Bonds. § 1–204.85. Tax exemption. § 1–204.86. Legal investment. § 1–204.87. Water pollution. § 1–204.88. Cost of reservoirs on Potomac River. § 1–204.89. District’s contributions to the Washington Metropolitan Area Transit Authority. § 1–204.90. Revenue bonds and other obligations.