Don has served as lead counsel in several nationally important first impression lawsuits limiting the scope of liability under federal statutes governing hazardous substances. Don has also litigated environmental cost recovery cases, several times recovering judgments for 100% of cleanup costs, and is regularly involved in enforcement cases before state and federal agencies and with the Department of Justice. He has litigated toxic tort cases, handling expert witnesses in numerous scientific and medical disciplines, as well as legal strategy and argument. He has also litigated novel cases under the commercial laws, including the securities laws and the rental housing conversion laws.

Don has also counseled clients on business structure and liability questions as they affect the intersection of real estate transactions and the environmental laws, bringing an appreciation of business entity design and transactional needs, as well as the legal, technical, and financial implications of pollution to the negotiating table. In other situations, unforeseen conditions in acquired properties have resulted in subsequent disputes that have been resolved to the purchaser's satisfaction. Using Don's skills, Arent Fox's business clients can achieve a comprehensive solution to environmental questions while achieving business goals.

Among Don’s trials and arbitrations is the following selection of reported decisions:

• 1325 G Street Assocs. v. Rockwood Pigments NA, Inc., 2004 WL 2191709 (D. Md. 2004), and 235 F. Supp. 2d 458 (D. Md. 2002)
• Gould, Inc. v. A&M Battery and Tire Service, Inc., 232 F.3d 162 (3d Cir. 2000), rev’g, 987 F. Supp. 353 (M.D. Pa. 1997), on remand, 176 F. Supp. 2d 324 (M.D. Pa. 2001)
• Joslyn Mfg. Co v. T.L. James & Co., 696 F. Supp. 222 (W.D. La. 1988), aff’d, 893 F.2d 80 (5th Cir. 1990)
• 1618 Twenty-First Street Tenants’ Ass’n, Inc. v. The Phillips Collection, 829 A.2d 201 (D.C. 2003)
• Northwestern Mutual Life Ins. Co v. Atlantic Research Corp., 847 F. Supp 389 (E.D. Va. 1994)
• Foster v. United States, 130 F. Supp. 2d 68 (D.D.C. 2001
• National Telephone Coop. Assoc. v. Exxon Corp., 38 F. Supp. 2d 1 (D.D.C. 1998); 244 F. 3d 153 (D.C. Cir. 2001)
• Safeway, Inc. v. CESC Plaza Ltd. P’ship., 261 F. Supp. 2d 439 (E.D. Va. 2003)
• Badlands Trust Co. v. First Financial Corp., 224 F. Supp. 2d 1033 (D. Md. 2002), rev’d, 2003 WL 194858 (4th Cir. 2003)
• Neuberger Berman Real Estate Income Fund, Inc. v. Lola Brown Trust No. 1, 485 F. Supp. 2d 631 (D. Md. 2007)

Don’s clients have included companies such as Konterra Development, LLC, Metalico, Inc., Safeway, Inc., Apex Companies, LLC, and Badlands Trust Company.