On November 13, 1978, the City of Pittsburg, California added the following provision to its criminal trespass ordinance:

No United States Postal Letter Carrier shall be allowed to cross the lawns of private property owners, lessee, or persons in charge thereof, without the prior express consent of the owner, lessee, or other person in charge thereof.

The United States and the United States Postal Service brought suit December 21, 1978, seeking declaratory and injunctive relief against enforcement of the amended provision of the ordinance. They argued that it interposed "an obstacle to the accomplishment and execution of the full purposes and objectives of Congress as expressed in the Postal Reorganization Act of 1971 and is in violation of Article I, Section 8, Clause 7 (the Postal Powers Clause) of the Constitution of the United States." The National Association of Letter Carriers (NALC), the exclusive collective bargaining agent for all non-supervisory postal employees in the city, was permitted to intervene as a defendant February 20, 1979. On April 2, 1979, the district court granted summary judgment to the United States and the Postal Service declaring the ordinance invalid under the Supremacy Clause. The City of Pittsburg and NALC (hereinafter referred to collectively as "the City") appealed.

The City argues that the Postal Reorganization Act, 39 U.S.C. § 101 et seq., does not preempt the ordinance because Congressional intent to override local trespass law is lacking. According to the City, in order for the ordinance to be preempted, there must also be an actual and necessary conflict with a federal statute that prevents the accomplishment of the federal purpose. Because the ordinance does not prevent the delivery of mail, the city argues, it does not present a direct and necessary conflict with Congressional purposes.

The City's emphasis on Congressional intent is misplaced. As the district court properly determined, Congress need not have intended specifically to override local trespass law for us to hold the application of the ordinance to the Postal Service invalid. It is undisputed that each government has acted in an area of its acknowledged power: The City in the area of local property rights and Congress in the area of postal service. The issue here is which government shall prevail if the otherwise legitimate exercise of authority of each results in a conflict. Local law will be found to be preempted by federal law whenever the "challenged state statute 'stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress.' " Perez v. Campbell, 402 U.S. 637, 649, 91 S.Ct. 1704, 1711, 29 L.Ed.2d 233 (1971) (quoting Hines v. Davidowitz, 312 U.S. 52, 67, 61 S.Ct. 399, 404, 85 L.Ed. 581 (1941)). See also Rust v. Johnson, 597 F.2d 174, 179 (9th Cir.), cert. denied, 444 U.S. 964, 100 S.Ct. 450, 62 L.Ed.2d 376 (1979) (local government cannot override federal interest even though local government was engaged in valid state function). Thus, we must determine whether the Pittsburg ordinance obstructs the execution of Congressional objectives in the area of mail delivery.

The conflict here between federal and local law is clear. The local ordinance prohibits postal carriers from crossing lawns unless they first obtain the owner's express consent. Federal law, on the other hand, authorizes postal carriers to cross lawns unless the owner objects. Postal regulations provide that "(c)arriers may cross lawns while making deliveries if patrons do not object and there are no particular hazards to the carrier."^[1]

It is also clear that the local ordinance frustrates a major Congressional objective that the postal regulation seeks to implement. The federal regulation is designed to promote the efficiency of mail delivery by permitting postal carriers to take short-cuts across lawns.^[2] The regulation's purpose and effect is consonant with the Congressional mandate to the Postal Service to provide efficient mail delivery service.^[3] The local ordinance frustrates postal efficiency by forcing the Postal Service either to stop using short-cuts across lawns or to undertake the nightmarish administrative burden of obtaining express consent from every Pittsburg property owner.^[4] It is therefore an unconstitutional "obstacle to the accomplishment and execution of the full purposes and objectives of Congress." Hines v. Davidowitz, 312 U.S. 52, 67, 61 S.Ct. 399, 404, 85 L.Ed. 581 (1941).

Our conclusion that the City's ordinance cannot be applied to federal postal carriers also follows from Johnson v. Maryland, 254 U.S. 51, 41 S.Ct. 16, 65 L.Ed. 126 (1920). Johnson held unconstitutional the application of a Maryland driver's license statute to postal employees. The court ruled that where a postal worker is performing duties pursuant to federal law, a state cannot impose requirements that interfere with the performance of those duties. Id. at 56-57, 41 S.Ct. at 16. Like the application of the statute in Johnson, the Pittsburg ordinance interferes with postal carriers' federal duty to deliver the mail efficiently and is therefore unconstitutional.^[5]

The City argues that even if the Postal Reorganization Act preempts the ordinance, the Act as applied violates the Tenth Amendment as interpreted in National League of Cities v. Usery, 426 U.S. 833, 96 S.Ct. 2465, 49 L.Ed.2d 245 (1976). The district court found the City's Tenth Amendment argument to be meritless. We agree. Usery applies only when federal activity encroaches upon integral governmental functions of the states or their political subdivisions. 426 U.S. at 855, 96 S.Ct. at 2475. Here, no integral governmental function of the City of Pittsburg is threatened by allowing postal carriers to cross lawns in the absence of customer objection. Usery, therefore, does not apply here.

The City also argues that the Postal Service practice of permitting letter carriers to cross lawns without express owner consent is a taking without just compensation in violation of the Fifth Amendment. This argument is meritless.

First, the City of Pittsburg does not have standing to raise the Fifth Amendment issue. It argues that it should be allowed to assert the rights of the local residents since it would be difficult for local residents to do so. The Supreme Court has established that even where a party is allowed to assert the rights of others, he "still must allege a distinct and palpable injury to himself" to possess standing. Warth v. Seldin, 422 U.S. 490, 501, 95 S.Ct. 2197, 2206, 45 L.Ed.2d 343 (1975); see also Gladstone, Realtors v. Village of Bellwood, 441 U.S. 91, 99-100, 99 S.Ct. 1601, 1607-1608, 60 L.Ed.2d 66 (1979). Here, the City of Pittsburg can assert no right of its own that is violated as a result of the postal carriers' lawn crossing. Nor may the City of Pittsburg base standing upon a parens patriae theory. Although cities may "sue to vindicate such of their own proprietary interests as might be congruent with the interests of their inhabitants," only the states and the federal government may sue as parens patriae. In Re Multidistrict Vehicle Air Pollution M.D.L. No. 31, 481 F.2d 122, 131 (9th Cir.), cert. denied sub nom. Morgan v. Automobile Manufacturers Ass'n, Inc., 414 U.S. 1045, 94 S.Ct. 551, 38 L.Ed.2d 336 (1973).

Second, even if the City had standing to raise the taking issue, the lawn-crossing policy's effect upon existing property rights is simply too miniscule to constitute a taking. The regulation does not significantly dilute or affect property rights or interests. It instead leaves property owners in full control of their property. The regulation and the record indicate that if a postal customer objects in any manner to having his lawn crossed, postal carriers will not cross the lawn. The regulation therefore does not effect a taking. See United States v. City of St. Louis, Branch 343, Nat. Ass'n. of Letter Carriers, 597 F.2d 121, 125 (8th Cir. 1979).

AFFIRMED.