Before this Court is the appeal of Soil Remediation Systems, Inc. (SRS) to the decision of the Environmental Hearing Board (EHB), that dismissed as untimely SRS’s appeal of a decision of the Department of Environmental Protection (DEP), that denied SRS’s request for an extension of a plan approval. We vacate and remand.

By letter dated October 25, 1996, SRS requested that DEP extend a plan approval set to expire on November 30, 1996. On December 6, 1996, DEP sent by facsimile a copy of a letter purportedly denying the extension request. The cover sheet of this facsimile was marked “advanced copy.” Also on December 6, 1996, DEP sent the original copy of the letter to SRS via certified mail. SRS acknowledges receipt of the facsimile on Friday, December 6,1996, and receipt of the original copy sent via certified mail on Monday, December 9,1996.

On January 6,1997, SRS mailed a notice of appeal of DEP’s decision to EHB. The notice of appeal was received and filed the next day, *1083January 7, 1997.1 Thereafter, EHB dismissed SRS’s appeal as being untimely, finding that pursuant to Section 10.2 of the Air Pollution Control Act (Act),2 SRS had thirty days from actual or constructive notice to file an appeal, and that the facsimile received on December 6,1996 was sufficient to constitute actual notice.

When reviewing decisions of the EHB, our scope of review is limited to determining whether constitutional rights were violated, an error of law was committed, or necessary findings of fact are not supported by substantial evidence. Al Hamilton Contracting Co. v. Department of Environmental Protection, 680 A.2d 1209 (Pa.Cmwlth. 1996). The sole issue on appeal is a question of law: to wit, whether DEP’s facsimile marked “advanced notice” received on December 6, 1996, or the certified letter received December 9, 1996,3 triggered the thirty-day appeal period. For the reasons discussed below, we find that the receipt of the certified letter commenced the thirty-day appeal period and that EHB erred by dismissing SRS’s appeal as untimely.

SRS contends that the appeal' period should have started on December 9,1996, the day it received the certified letter notifying it of DEP’s decision not to grant the requested extension of its plan approval. In support of this contention, SRS makes two arguments. First, SRS argues that pursuant to Section 6.1(e) of the Act, 35 P.S. § 4006.1(e),4 DEP is required to serve notice of its determination via certified mail, and the appeal period should begin upon receipt of the certified letter. Second, SRS argues that assuming DEP was not required to send notice via certified mail, receipt of the letter still triggered the appeal period in this ease since the facsimile marked “advance copy” was insufficient notice to apprise SRS of DEP’s action.5

*1084A discussion of the merits of SRS’s first argument is unnecessary, as the disposition of this case hinges on the inadequacy of DEP’s December 6, 1996 facsimile. Section 10.2 of the Act grants a party aggrieved by a DEP determination issued pursuant to the Act thirty days from actual or constructive notice of the decision to appeal. 35 P.S. § 4010.2. Inherent in this appeal process is the fact that a determination must be final before it can be appealed, and the finality of the decision must be communicated to the affected parties. See Pugar v. Greco, 483 Pa. 68, 72-73, 394 A.2d 542, 545 (1978) (remarking that “[i]t is, of course, well settled that an appeal will lie only from a final order unless otherwise permitted by statute”) (citations omitted); Milford Township Board of Supervisors v. Department of Environmental Resources, 165 Pa.Cmwlth. 14, 644 A.2d 217, 219 (1994) (asserting that “[c]onstitutionally adequate notice of administrative action is notice which is reasonably calculated to apprise interested parties of the pendency of the action and afford them an opportunity to present their objections”) (citations omitted). What constitutes a final administrative decision is determined by a practical rather than technical construction of the decision. Lehigh Township v. Department of Environmental Resources, 154 Pa.Cmwlth. 647, 624 A.2d 693, 696 (1993) (citing Pugar). Additionally, the inclusion of conditional language is a good indication that an administrative determination is not final. Id. (citing Department of Transportation v. Andrews, 143 Pa.Cmwlth. 601, 600 A.2d 622 (1991)).

In the present case, SRS was not apprised of the finality of DEP’s determination until it received the certified letter on December 9, 1996. This Court’s practical construction of the “advanced copy” notation on the facsimile leads to the conclusion that it was reasonable for SRS to have believed that this was not the operative notice for purpose of appeal. The inclusion of the conditional language in and of itself made the notice defective. Moreover, when viewed in conjunction with the receipt of the certified letter sometime thereafter, which included the language “[a]ppeals must be filed with the Environmental Hearing Board within 30 days of receipt of written notice of this action” (as did the so called “advanced copy”), we feel that it was even moré understandable that SRS relied on the certified letter as the operative notice for purposes of the thirty-day appeal period.

Accordingly, EHB’s order dismissing SRS’s appeal as untimely is hereby vacated; and this case is remanded to EHB for a hearing on the merits of DEP’s decision not to grant SRS’s request for extension of its plan approval.

ORDER

AND NOW, this 22nd day of December, 1997, the order of the Environmental Hearing Board in the above-captioned matter is vacated, and this matter is remanded to the Board for a hearing on the merits of the Department of Environmental Protection’s decision to deny SRS’s request for extension of its plan approval.

Jurisdiction relinquished.