The following activities shall be exempt from the Unified Nontidal Wetland Permit and mitigation requirements of this Ordinance, but are subject to MDNR regulations under COMAR 08.05.04.13 and .15 through .18; Forestry activities conducted in accordance with COMAR 08.05.04.20 and .21: Agricultural activities in Regulation COMAR .08.05.04.19B. All other agricultural activities shall be exempt from the permit requirements of this Ordinance, but are subject to the mitigation requirements of COMAR .08.05.04.13 and .15 through .18; Activities conducted by State agencies; and Activities conducted in Nontidal Wetlands of Special State Concern. Any proposed regulated activity conducted by a person who has applied to the U.S. Army Corps of Engineering by December 31, 1990, for a permit under Section 404 of the Clean Water Act is exempt from the Joint State/County Wetland permit requirement provided that the following conditions are satisfied: The U.S. Army Corps of Engineers ultimately issues a permit or other document under subsection (b)(3)(C); The applicant does not alter the scope of the regulated activity originally applied for without authorization from the U.S. Army Corps of Engineers. A person submits the following information to the Department, as may be applicable, and as may be requested by the Department: A copy of a dated application for a permit under Section 404 of the Clean Water Act; A copy of the plans for the project which were submitted to the Corps; and A letter from the Corps describing the project and proposed activity and stating either: The project and proposed activity is authorized by the Corps; or The proposed activity is exempt from Section 404 permit requirements. The following activities shall be exempt from the Unified Nontidal Wetland Permit, provided they do not result in cumulative direct or indirect adverse impacts: Construction of additions, outbuildings and accessories to existing structures within a landscape management area which impacts less than 1,000 square feet of nontidal wetlands; Construction placed on existing impervious surfaces or on structures within the buffer or expanded buffer; Removal of 30 percent of the trees in the buffer provided that: The density, but not the areal extent of the trees, is reduced; No more than 30 percent of the understory is removed; and Clearing is in conformance with the applicable Type I and/or Type II Tree Conservation Plan; Moving or other forms of vegetation control on existing rights-of-way; The control of State designated noxious weeds; Landscape management in the nontidal wetland, buffer or expanded buffer; Soil investigations; Percolation tests for sewage disposal fields; Survey markers or survey monuments; Other similar activities with minimal adverse impacts as approved by the Department and MDNR; The maintenance of the following serviceable structures or fills: Above and underground utilities; Structures in rights-of-way; Railroad beds; Road beds, roadside ditches, culverts, outlet ditches, wash ponds and temporary sediment control structures; Bridges; Dams; Dikes; Levees; Water and wastewater control structures; and Facilities designed for stormwater management.