Before this court, appellants’ sole challenge to the commission’s order is the propriety of allowing DP&L to recover the additional expenses for line clearance. Appellants argue that the inclusion of the additional sum violates the test year concepts contained in R.C. 4909.15. In support of its position, appellants rely on Consumers’ Counsel (EOG), supra.
In Consumers’ Counsel (EOG), the commission allowed a post-test-year adjustment to East Ohio Gas for increased labor expenses due to the signing of a new labor contract. Upon appeal, this court reversed. We held that R.C. 4909.15(A) precluded East Ohio Gas from recovering post-test-year expenses. However, we recognized that: “In certain circumstances, of course, inclusion of costs not incurred in the test year is proper.” 67 Ohio St. 2d at 376.
Here, the commission, upon applications for rehearing, found that because of the unique circumstances present, Consumers’ Counsel (EOG) was not a bar to the additional allowance. We agree; therefore, we affirm.
This court has consistently held that we will not disturb the final order of the commission absent a showing of misapprehension, mistake or willful disregard of duty. Columbus v. Pub. Util. Comm. (1979), 58 Ohio St. 2d 103, *127104 [12 O.O.3d 112]; Consumers’ Counsel v. Pub. Util. Comm. (1981), 67 Ohio St. 2d 153, 156 [21 O.O.3d 96]. Consequently, we must decide whether allowing the post-test-year adjustment in this case, given these unique circumstances constituted mistake, misapprehension or willful disregard of duty by the commission.
As a starting point, the above-quoted language from Consumers’ Counsel (EOG) makes it clear that we did not adopt a per se rule which would preclude all post-test-year adjustments. Rather, while not elaborating, we stated that adjustments would be allowed in certain circumstances. Are these proper circumstances? For reasons that follow, we hold that this is a proper case for the allowance of a post-test-year adjustment.
The uncontroverted testimony, here, was that DP&L had not kept its lines as clear as necessary to provide safe, efficient service. If DP&L does not improve its performance in this area, more power lines will be damaged with a consequent increase in power outages. This will lead to safety hazards for both DP&L’s customers and its employees. See R.C. 4905.06. Additionally, costs will increase with delay. DP&L will be forced to spend more money on repairs, and delay in implementing the recommended plan will render it more expensive.
Further, R.C. 4909.15(D)7 provides for adjustments in a utility’s rates when they are “insufficient to yield reasonable compensation for the service rendered.” In Consumers’ Counsel v. Pub. Util. Comm., supra, we stated that R.C. 4909.15(D) gives the commission the authority to “smooth out anomalies in the ratemaking equation that tend to make the test year data unrepresentative for ratemaking purposes.” 67 Ohio St. 2d at 166.
Where, as here, the commission orders a utility to adopt a specific plan to assure continued safe, efficient service, R.C. 4909.15(D) provides sufficient statutory authority for post-test-year adjustments. To disallow this adjustment would result in an anomaly in the ratemaking equation, making the test year unrepresentative for ratemaking purposes.
Accordingly, the commission’s order is affirmed.
Order affirmed.
*128Celebrezze, C.J., W. Brown, Sweeney, Holmes, C. Brown and Krupansky, JJ., concur.R.C. 4909.15(D) provides, in pertinent part:
“When the public utilities commission is of the opinion, after hearing and after making the determinations under divisions (A) and (B) of this section * * * that the maximum rates * * * chargeable by any such public utility are insufficient to yield reasonable compensation for the service rendered, and are unjust and unreasonable, the commission shall:
<<* * *
“(2) With due regard to all such other matters as are proper, according to the facts in each case,
a * * *
“(b) * * * fix and determine the just and reasonable rate * * * that will provide the public utility the allowable gross annual revenues under division (B) of this section, and order such just and reasonable rate * * * to be substituted for the existing one.* * *”